論文 - RAHMAN Abidur
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Actin isovariant ACT2-mediated cellular auxin homeostasis regulates lateral root organogenesis in Arabidopsis thaliana
Hanzawa A, Rahman AA, Rahman A
Cytoskeleton ( Willey ) 0 1-13 2024年11月 [査読有り]
学術誌 共著・分担
Lateral root (LR) organogenesis is regulated by cellular flux of auxin within pericycle cells, which depends on the membrane distribution and polar localization of auxin carrier proteins. The correct distribution of auxin carrier proteins relies on the intracellular trafficking of these proteins aided by filamentous actin as a track. However, the precise role of actin in lateral root development is still elusive. Here, using vegetative class actin isovariant mutants, we revealed that loss of actin isovariant ACT8 led to increased lateral root formation. The distribution of auxin within pericycle cells was altered in act8 mutant, primarily due to the altered distribution of AUX1 and PIN7. Interestingly, incorporation of act2 mutant in act8 background (act2act8) effectively nullified the LR phenotype observed in act8 mutant, indicating that ACT2 plays an important role in LR development. To explore further, we investigated the possibility that the act8 mutant's LR phenotype and cellular auxin distribution resulted from ACT2 overexpression. Consistent with the idea, enhanced lateral root formation, altered AUX1, PIN7 expression, and auxin distribution in pericycle cells were observed in ACT2 overexpression lines. Collectively, these results suggest that actin isovariant ACT2 but not ACT8 plays a pivotal role in regulating source-to-sink auxin distribution during lateral root organogenesis.
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Comparative metabolite profiling of salt sensitive Oryza sativa and the halophytic wild rice Oryza
Tamanna N, Mojumder A, Azim T, Iqbal MI, Alam MNU, Rahman A, Seraj ZI
Plant-Environment Interactions ( Willey ) 5 ( 3 ) e10155 2024年05月 [査読有り]
学術誌 共著・分担
To better understand the salt tolerance of the wild rice, Oryza coarctata, root tissue-specific untargeted comparative metabolomic profiling was performed against the salt sensitive Oryza sativa. Under control, O. coarctata exhibited abundant levels of most metabolites, while salt caused their downregulation in contrast to metabolitesin O. sativa. Under control conditions, itaconate, vanillic acid, threonic acid, eicosanoids, and a group of xanthin compounds were comparatively abundant in O. coarctata. Similarly, eight amino acids showed constitutive abundance in O. coarctata. In contrast, under control, glycerolipid abundances were lower in O. coarctata and saltstress further reduced their abundance. Most phospholipids also showed a distribution similar to the glycerolipids. Fatty acyls were however significantly induced in O.coarctata but organic acids were prominently induced in O. sativa. Changes in metabolite levels suggest that there was upregulation of the arachidonic acid metabolism in O. coarctata. In addition, the phenylpropanoid biosynthesis as well as cutin, suberin,and wax biosynthesis were also more enriched in O. coarctata, likely contributing to its anatomical traits responsible for salt tolerance. The comparative variation in the number of metabolites like gelsemine, allantoin, benzyl alcohol, specific phospholipids,and glycerolipids may play a role in maintaining the superior growth of O. coarctata insalt. Collectively, our results offer a comprehensive analysis of the metabolite profile in the roots of salt-tolerant O. coarctata and salt-sensitive O. sativa, which confirm potential targets for metabolic engineering to improve salt tolerance and resilience in commercial rice genotypes.
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Heat stress impairs floral meristem termination and fruit development by affecting the BR-SlCRCa cascade in tomato
Junqing Wu , Wenru Sun, Chao Sun, Chunmiao Xu, Shuang Li, Pengxue Li, Huimin Xu, Danyang Zhu, Meng Li, Liling Yang, Jinbo Wei, Aya Hanzawa, Sumaiya Jannat Tapati, Reiko Uenoyama, Masao Miyazaki, Abidur Rahman, Shuang Wu
Plant Communications ( Cell Press ) 5 ( 8 ) 100790 2024年04月 [査読有り]
学術誌 共著・分担
Floral meristem termination is a key step leading to carpel initiation and fruit development. The frequent occurrence of heat stress due to global warming often disrupts floral determinacy, resulting in defective fruit formation. However, the detailed mechanism behind this phenomenon is largely unknown. Here, we identify CRABS CLAW a (SlCRCa) as a key regulator of floral meristem termination in tomato. SlCRCa functions as an indispensable floral meristem terminator by suppressing SlWUS activity through the TOMATO AGAMOUS 1 (TAG1)–KNUCKLES (SlKNU)–INHIBITOR OF MERISTEM ACTIVITY (SlIMA) network. A direct binding assay revealed that SlCRCa specifically binds to the promoter and second intron of WUSCHEL (SlWUS). We also demonstrate that SlCRCa expression depends on brassinosteroid homeostasis in the floral meristem, which is repressed by heat stress via the circadian factor EARLY FLOWERING 3 (SlELF3). These results provide new insights into floral meristem termination and the heat stress response in flowers and fruits of tomato and suggest that SlCRCa provides a platform for multiple protein interactions that may epigenetically abrogate stem cell activity at the transition from floral meristem to carpel initiation.
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SlCRCa is a key D-class gene controlling ovule fate determination in tomato
Junqing Wu, Pengxue Li, Danyang Zhu, Haochuan Ma, Meng Li, Yixuan Lai, Yuxin Peng, Haixiao Li, Shuang Li, Jinbo Wei, Xinxin Bia, Abidur Rahman and Shuang Wu
Plant Biotechnology Journal ( Willey ) 22 1966 - 1980 2024年02月 [査読有り]
学術誌 共著・分担
Cell fate determination and primordium initiation on the placental surface are two key events forovule formation in seed plants, which directly affect ovule density and seed yield. Despite ovulesform in the marginal meristematic tissues of the carpels, angiosperm carpels evolved after theovules. It is not clear how the development of the ovules and carpels is coordinated inangiosperms. In this study, we identify the S. lycopersicum CRABS CLAW (CRC) homologueSlCRCa as an essential determinant of ovule fate. We find that SlCRCa is not only expressed in theplacental surface and ovule primordia but also functions as a D-class gene to block carpel fateand promote ovule fate in the placental surface. Loss of function of SlCRCa causes homeotictransformation of the ovules to carpels. In addition, we find low levels of the S. lycopersicumAINTEGUMENTA (ANT) homologue (SlANT2) favour the ovule initiation, whereas high levels ofSlANT2 promote placental carpelization. SlCRCa forms heterodimer with tomato INNER NOOUTER (INO) and AGAMOUS (AG) orthologues, SlINO and TOMATO AGAMOUS1 (TAG1), to repress SlANT2 expression during the ovule initiation. Our study confirms that angiosperm basal ovule cells indeed retain certain carpel properties and provides mechanistic insights into the ovuleinitiation.t SlCRCa expression depends on brassinosteroid homeostasis in the floral meristem, which is repressed by heat stress via the circadian factor EARLY FLOWERING 3 (SlELF3). These results provide new insights into floral meristem termination and the heat stress response in flowers and fruits of tomato and suggest that SlCRCa provides a platform for multiple protein interactions that may epigenetically abrogate stem cell activity at the transition from floral meristem to carpel initiation.
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Cold stress induces malformed tomato fruits by breaking the feedback loops of stem cell regulation in floral meristem
Junqing Wu, Wenru Sun, Chao Sun, Chunmiao Xu, Shuang Li, Pengxue Li, Huimin Xu, Danyang Zhu, Meng Li, Liling Yang, Jinbo Wei, Aya Hanzawa, Sumaiya Jannat Tapati, Reiko Uenoyama, Masao Miyazaki, Abidur Rahman, Shuang Wu
New Phytologist ( Willey ) 237 ( 6 ) 2268 - 2283 2022年12月 [査読有り]
学術誌 共著・分担
Fruit malformation is a major constrain in fruit production worldwide resulting in substantial economic losses. The farmers for decades noticed that the chilling temperature before blooming often caused malformed fruits. However, the molecular mechanism underlying this phenomenon is unclear.
Here we examined the fruit development in response to cold stress in tomato, and demonstrated that short-term cold stress increased the callose accumulation in both shoot apical and floral meristems, resulting in the symplastic isolation and altered intercellular movement of WUS.
In contrast to the rapidly restored SlWUS transcription during the recovery from cold stress, the callose removal was delayed due to obstructed plasmodesmata. The delayed reinstatement of cell-to-cell transport of SlWUS prevented the activation of SlCLV3 and TAG1, causing the interrupted feedback inhibition of SlWUS expression, leading to the expanded stem cell population and malformed fruits. We further showed that the callose dynamics in response to short-term cold stress presumably exploits the mechanism of bud dormancy during the seasonal growth, involving two antagonistic hormones, abscisic acid and gibberellin.
Our results provide a novel insight into the cold stress regulated malformation of fruit. -
Actin isovariant ACT7 controls root meristem development in Arabidopsis through modulating auxin and ethylene responses
Takahiro Numata, Kenji Sugita, Arifa Ahamed Rahman, Abidur Rahman
Journal of Experimental Botany ( Oxford Academic ) 73 ( 18 ) 6255 - 6271 2022年10月 [査読有り]
学術誌 共著・分担
The meristem is the most functionally dynamic part in a plant. The shaping of the meristem requires constant cell division and elongation, which are influenced by hormones and the cytoskeletal component, actin. Although the roles of hormones in modulating meristem development have been extensively studied, the role of actin in this process is still elusive. Using the single and double mutants of the vegetative class actin, we demonstrate that actin isovariant ACT7 plays an important role in root meristem development. In the absence of ACT7, but not ACT8 and ACT2, depolymerization of actin was observed. Consistently, the act7 mutant showed reduced cell division, cell elongation, and meristem length. Intracellular distribution and trafficking of auxin transport proteins in the actin mutants revealed that ACT7 specifically functions in the root meristem to facilitate the trafficking of auxin efflux carriers PIN1 and PIN2, and consequently the transport of auxin. Compared with act7, the act7act8 double mutant exhibited slightly enhanced phenotypic response and altered intracellular trafficking. The altered distribution of auxin in act7 and act7act8 affects the response of the roots to ethylene, but not to cytokinin. Collectively, our results suggest that ACT7-dependent auxin-ethylene response plays a key role in controlling Arabidopsis root meristem development.
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Genetic diversity of field mustard (Brassica Rapa L.) and their staurated and unsaturated fatty acids association
Rahman J, Sultana F, Fatima K, Hassan MM, Gain N, Hossain MS, Chowdhury AK, Rahman A
SABRAO Journal of Breeding and Genetics ( SABARO ) 54 ( 2 ) 249 - 266 2022年05月 [査読有り]
学術誌 共著・分担
14 B. rapa cultivars differed significantly and were grouped into five diversified
clusters. The highest intra-cluster distance was found in cluster II (2.43), while the highest intercluster distance was found between clusters II and V (20.41). In the fatty acid profile, the maximum
threshold acceptable level (<7%) of saturated fatty acids for human consumption was found in Sonali
Sarisha and BARI Sarisha-14. The total monounsaturated fatty acids viz., oleic, eicosenoic, and erucic
acid ranged from 62.74% in BARI Sarisha-15 to 69.51% in Sonali Sarisha. The highest oleic acid and
eicosenoic acid were obtained from the local variety, Maghi (21.06%) and Improved Tori (9.08%). The
highest essential linoleic and linolenic acids were found in BARI Sarisha-15 (17.10%) and Improved
Tori (8.16%), respectively. However, the local cultivar Maghi, containing the highest oleic acid
(21.06%) has the lowest erucic acid (35.53%). On the other hand, BARI Sarisha-14 contained the
lowest oleic (17.22%) and the highest erucic (44.02%) acids. The negative and strong correlation also
reinforced the reverse relationship between oleic and erucic acids. Similarly, both linoleic (-0.497) and
linolenic (-0.443) acids also showed a negative correlation with erucic acid. As a whole, BARI Sarisha14, BARI Sarisha-15, Maghi, Sonali Sarisha, and Improved Tori could be selected as potential parents
for a hybridization program to breed potential recombinant lines with higher oil content and healthier
unsaturated oleic and linoleic fatty acids. -
Actin isovariant ACT7 modulates root thermomorphogenesis by altering intracellular auxin homeostasis
Parveen S, Rahman A
International Journal of Molecular Science ( MDPI ) 22 ( 14 ) 7749 - 0 2021年07月 [査読有り]
学術誌 共著・分担
Although high temperature alters the intracellular trafficking, the role of actin in this process remains obscure. Using isovariant specific vegetative class actin mutants, here we demonstrate that ACTIN 7 (ACT7) isovariant plays an important role in regulating the moderate-high temperature response in Arabidopsis root. Loss of ACT7, but not ACT8 resulted in increased inhibition of root elongation under prolonged moderate-high temperature. Consistently, kinematic analysis revealed a drastic reduction in cell production rate and cell elongation in act7-4 mutant under high temperature. Quantification of actin dynamicity reveals that prolonged moderate-high temperature modulates bundling along with orientation and parallelness of filamentous actin in act7-4 mutant. The hypersensitive response of act7-4 mutant was found to be linked to the altered intracellular auxin distribution, resulted from the reduced abundance of PIN-FORMED PIN1 and PIN2 efflux carriers. Collectively, these results suggest that vegetative class actin isovariant, ACT7 modulates the long-term moderate-high temperature response in Arabidopsis root.
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Ashraf MA, Akihiro T, Ito K, Kumagai S, Sugita R, Tanoi K, Rahman A
Molecular Plant ( Cell Press; Elsevier ) 14 ( 4 ) 664 - 678 2021年02月 [査読有り]
学術誌 共著・分担
Radiocesium accumulated in the soil by nuclear accidents is a major environmental concern. The transport process of cesium (Cs+) is tightly linked to the indispensable plant nutrient potassium (K+) as they both belong to the group I alkali metals with similar chemical properties. Most of the transporters that had been characterized to date as Cs+ transporters are directly or indirectly linked to K+. Using a combinatorial approach of physiology, genetics, cell biology, and root uptake assay, here we identified two ATP-binding cassette (ABC) proteins, ABCG37 and ABCG33, as facilitators of Cs+ influx. A gain-of-function mutant of ABCG37 (abcg37-1) showed increased sensitivity to Cs+-induced root growth inhibition, while the double knockout mutant of ABCG33 and ABCG37 (abcg33-1abcg37-2) showed resistance, whereas the single loss-of-function mutants of ABCG33 and ABCG37 did not show any alteration in Cs+ response. In planta short-term radioactive Cs+-uptake assay along with growth and uptake assays in a heterologous system confirmed ABCG33 and ABCG37 as Cs+-uptake carriers. Potassium response and content were unaffected in the double-mutant background and yeast cells lacking potassium-uptake carriers transformed with ABCG33 and ABCG37 failed to grow in the absence of K+, confirming that Cs+ uptake by ABCG33 and ABCG37 is independent of K+. Collectively, this work identified two ABC proteins as new Cs+-influx carriers that act redundantly and independent of the K+-uptake pathway.
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Rahman T, Shao M, Pahari S, Venglat P, Soolanayakanahally R, Qiu X, Rahman A, Tanino K
International Journal of Molecular Science ( MDPI ) 14 ( 4 ) 1554 - 0 2021年02月 [査読有り]
学術誌 共著・分担
The present study investigated the role of cuticular wax in
reducing both low-temperature and dehydration stress in plants using Arabidopsis thaliana mutants
and transgenic genotypes altered in the formation of cuticular wax. cer3-6, a known Arabidopsis waxdeficient mutant (with distinct reduction in aldehydes, n-alkanes, secondary n-alcohols, and ketones
compared to wild type (WT)), was most sensitive to water loss, while dewax, a known wax overproducer (greater alkanes and ketones compared to WT), was more resistant to dehydration compared to
WT. Furthermore, cold-acclimated cer3-6 froze at warmer temperatures, while cold-acclimated dewax
displayed freezing exotherms at colder temperatures compared to WT. Gas Chromatography-Mass
Spectroscopy (GC-MS) analysis identified a characteristic decrease in the accumulation of certain
waxes (e.g., alkanes, alcohols) in Arabidopsis cuticles under cold acclimation, which was additionally
reduced in cer3-6. Conversely, the dewax mutant showed a greater ability to accumulate waxes under
cold acclimation. Fourier Transform Infrared Spectroscopy (FTIR) also supported observations in
cuticular wax deposition under cold acclimation. Our data indicate cuticular alkane waxes along
with alcohols and fatty acids can facilitate avoidance of both ice formation and leaf water loss under
dehydration stress and are promising genetic targets of interest. -
Aux/IAA14 Regulates microRNA-Mediated Cold Stress Response in Arabidopsis Roots
Aslam M,Sugita K, Qin Y, Rahman A
International Journal of Molecular Sciences ( MDPI ) 21 ( 22 ) 8441 2020年11月 [査読有り]
学術誌 共著・分担
To understand the role of microRNA (miR) in the crosstalk between auxin and cold stress responses, we took advantage of the mutants of Arabidopsis thaliana with altered response to auxin transport and signal. Screening of the mutants for root growth recovery after cold stress at 4 °C revealed that the auxin signaling mutant, solitary root 1 (slr1; mutation in Aux/IAA14), shows a hypersensitive response to cold stress. Genome-wide expression analysis of miRs in the wild-type and slr1 mutant roots using next-generation sequencing revealed 180 known and 71 novel cold-responsive microRNAs. Cold stress also increased the abundance of 26–31 nt small RNA population in slr1 compared with wild type. Comparative analysis of microRNA expression shows significant differential expression of 13 known and 7 novel miRs in slr1 at 4 °C compared with wild type. Target gene expression analysis of the members from one potential candidate miR, miR169, revealed the possible involvement of miR169/NF-YA module in the Aux/IAA14-mediated cold stress response. Taken together, these results indicate that SLR/IAA14, a transcriptional repressor of auxin signaling, plays a crucial role in integrating miRs in auxin and cold responses.
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Rahman A, Kawamura Y, Maeshima M, Rahman A, Uemura M
Plant and Cell Physiology ( Oxford Academics ) 61 ( 4 ) 787 - 802 2020年01月 [査読有り]
学術誌 共著・分担
Aquaporins play a major role in plant water uptake at both optimal and environmentally stressed conditions. However, the functional specificity of aquaporins under cold remains obscure. To get a better insight to the role of aquaporins in cold acclimation and freezing tolerance, we took an integrated approach of physiology, transcript profiling and cell biology in Arabidopsis thaliana. Cold acclimation resulted in specific upregulation of PIP1;4 and PIP2;5 aquaporin (plasma membrane intrinsic proteins) expression, and immunoblotting analysis confirmed the increase in amount of PIP2;5 protein and total amount of PIPs during cold acclimation, suggesting that PIP2;5 plays a major role in tackling the cold milieu. Although single mutants of pip1;4 and pip2;5 or their double mutant showed no phenotypic changes in freezing tolerance, they were more sensitive in root elongation and cell survival response under freezing stress conditions compared with the wild type. Consistently, a single mutation in either PIP1;4 or PIP2;5 altered the expression of a number of aquaporins both at the transcriptional and translational levels. Collectively, our results suggest that aquaporin members including PIP1;4 and PIP2;5 function in concert to regulate cold acclimation and freezing tolerance responses.
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PIN Formed 2 modulates the transport of arsenite in Arabidopsis thaliana
Ashraf MA, Umetsu K, Ponomarenko O, Saito M, Aslam M, Antipova O, Dolgova N, Kiani CD, Susan Nezhati S, Tanoi K, Minegishi K, Nagatsu K, Kamiya T, Fujiwara T, Luschnig C, Tanino K, Pickering I, George GN, Rahman A
Plant Communications ( Cell Press; Elsevier ) 1 ( 3 ) 1 - 15 2019年11月 [査読有り]
学術誌 共著・分担
Arsenic contamination is a major environmental issue, as it may lead to serious health hazard. The reduced trivalent form of inorganic arsenic, arsenite, is in general more toxic to plants compared with the fully oxidized pentavalent arsenate. The efflux mechanisms, as well as the mechanism of arsenite-induced root growth inhibition, remain poorly understood. Using molecular physiology, synchrotron imaging, and root transport assay approaches, we show that the cellular transport of trivalent arsenicals in Arabidopsis thaliana is strongly modulated by PIN FORMED 2 (PIN2) auxin efflux transporter.
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Cold stress response in Arabidopsis thaliana is mediated by GNOM ARF-GEF
Ashraf MA, Rahman A
Plant Journal 97 ( 3 ) 500 - 516 2019年02月 [査読有り]
国際的学術誌 共著・分担
Arabidopsis root is directly linked to inhibition of the endosomal trafficking of auxin efflux carriers. However, the cellular components that link cold stress and the endosomal trafficking remain elusive. By screening available endosomal trafficking mutants against root growth recovery response under cold stress, we identified GNOM, a SEC7 containing ARF‐GEF, as a major modulator of cold response. Contrasting response of partial loss of function mutant gnomB4049/emb30‐1 and the engineered Brefeldin A (BFA)‐resistant GNOM line, both of which contain mutations within SEC7 domain, to cold stress at the whole‐plant level highlights the importance of this domain in modulating the cold response pathway of plants. Cold stress selectively and transiently inhibits GNOM expression. The engineered point mutation at 696 amino acid position (Methionine to Leucine) that makes GNOM resistant to BFA in fact results in overexpression of GNOM both at transcriptional and translational levels........
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Maho T, Umetsu K, Oono Y, Higaki T, Blanclaflor EB, Rahman A
Plant Journal 89 940 - 956 2016年11月 [査読有り]
国際的学術誌 共著・分担
2,4-Dichlorophenoxyacetic acid (2,4-D), a functional analogue of auxin, is used as an exogenous source of auxin as it evokes physiological responses like the endogenous auxin, indole-3-acetic acid (IAA). Previousmolecular analyses of the auxin response pathway revealed that IAA and 2,4-D share a common mode ofaction to elicit downstream physiological responses. However, recent findings with 2,4-D-specific mutants suggested that 2,4-D and IAA might also use distinct pathways to modulate root growth in Arabidopsis. Using genetic and cellular approaches, we demonstrate that the distinct effects of 2,4-D and IAA on actin filament organization partly dictate the differential responses of roots to these two auxin analogues. 2,4-D but not IAA altered the actin structure in long-term and short-term assays. Analysis of the 2,4-D-specific mutant aar1-1 revealed that small acidic protein 1 (SMAP1) functions positively to facilitate the 2,4-D induced depolymerization of actin.
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Hanzawa A, Shibasaki A, Numata, T, Kawamura, K, Guade T, Rahman A
Plant Cell 25 3424 - 3433 2013年09月 [査読有り]
国際的学術誌 共著・分担
High-temperature-mediated adaptation in plant architecture is linked to the increased synthesis of the phytohormone auxin, which alters cellular auxin homeostasis. The auxin gradient, modulated by cellular auxin homeostasis, plays an important role in regulating the developmental fate of plant organs. Although the signaling mechanism that integrates auxin and high temperature is relatively well understood, the cellular auxin homeostasis mechanism under high temperature is largely unknown. Using the Arabidopsis thaliana root as a model, we demonstrate that under high temperature, roots counterbalance the elevated level of intracellular auxin by promoting shootward auxin efflux in a PIN-FORMED2 (PIN2)-dependent manner. Further analyses revealed that high temperature selectively promotes the retrieval of PIN2 from late endosomes and sorts them to the plasma membrane through an endosomal trafficking pathway dependent on SORTING NEXIN 1.
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Rahman A , Takahashi M, Shibasaki K, Wu S, Inaba T, Tsurumi S, Baskin TI
Plant Cell 22 ( 6 ) 1762 - 1776 2010年06月 [査読有り]
学術誌 共著・分担
Shootward polar auxin transport, and hence gravitropism, depends on the polar deployment of the PIN-FORMED auxin efflux carrier PIN2. In Arabidopsis thaliana, PIN2 has the expected shootward localization in epidermis and lateral root cap; however, this carrier is localized toward the root tip (rootward) in cortical cells of the meristem, a deployment whose function is enigmatic. We use pharmacological and genetic tools to cause a shootward relocation of PIN2 in meristematic cortical cells without detectably altering PIN2 polarization in other cell types or PIN1 polarization. This relocation of cortical PIN2 was negatively regulated by the membrane trafficking factor GNOM and by the regulatory A1 subunit of type 2-A protein phosphatase (PP2AA1) but did not require the PINOID protein kinase. When GNOM was inhibited, PINOID abundance increased and PP2AA1 was partially immobilized, indicating both proteins are subject to GNOM-dependent regulation.
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Auxin response under cold stress: underlying molecular mechanisms
Shibasaki K, Uemura M, Tsurumi S, Rahman A
Plant Cell 21 ( 12 ) 3823 - 3838 2009年12月 [査読有り]
学術誌 共著・分担
To understand the mechanistic basis of cold temperature stress and the role of the auxin response, we characterized root growth and gravity response of Arabidopsis thaliana after cold stress, finding that 8 to 12 h at 4°C inhibited root growth and gravity response by ∼50%. The auxin-signaling mutants axr1 and tir1, which show a reduced gravity response, responded to cold treatment like the wild type, suggesting that cold stress affects auxin transport rather than auxin signaling. Consistently, expression analyses of an auxin-responsive marker, IAA2-GUS, and a direct transport assay confirmed that cold inhibits root basipetal (shootward) auxin transport. Microscopy of living cells revealed that trafficking of the auxin efflux carrier PIN2, which acts in basipetal auxin transport, was dramatically reduced by cold. urthermore, the inhibition of protein trafficking by cold is independent of cellular actin organization and membrane fluidity.
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Genetic diversity of field mustard (Brassica Rapa L.) and their staurated and unsaturated fatty acids association
J. RAHMAN, F. SULTANA, K. FATIMA, M.M. HASAN, N. GAIN, M.S. HOSSAIN, A.K. CHOWDHURY, and A. RAHMAN
SABRAO Journal of Breeding and Genetics ( Society for the Advancement of Breeding Research in Asia and Oceania ) 54 ( 2 ) 249 - 266 2022年01月 [査読有り]
学術誌 共著・分担
The oilseed crop improvement for Brassica rapa L. (field mustard) is considered to be important in respect of yield production coupled with unsaturated fatty acids of the existing cultivars. Hence, the genetic diversity, and nutritional components of 14 B. rapa cultivars were evaluated based on their yield attributes and fatty acid profiles at the Sher-e-Bangla Agricultural University, Dhaka, Bangladesh. These 14 B. rapa cultivars differed significantly and were grouped into five diversified clusters. The highest intra-cluster distance was found in cluster II (2.43), while the highest intercluster distance was found between clusters II and V (20.41). In the fatty acid profile, the maximum threshold acceptable level (<7%) of saturated fatty acids for human consumption was found in Sonali Sarisha and BARI Sarisha-14. The total monounsaturated fatty acids viz., oleic, eicosenoic, and erucic acid ranged from 62.74% in BARI Sarisha-15 to 69.51% in Sonali Sarisha. The highest oleic acid and eicosenoic acid were obtained from the local variety, Maghi (21.06%) and Improved Tori (9.08%). The highest essential linoleic and linolenic acids were found in BARI Sarisha-15 (17.10%) and Improved Tori (8.16%), respectively. However, the local cultivar Maghi, containing the highest oleic acid (21.06%) has the lowest erucic acid (35.53%). On the other hand, BARI Sarisha-14 contained the lowest oleic (17.22%) and the highest erucic (44.02%) acids. The negative and strong correlation also reinforced the reverse relationship between oleic and erucic acids. Similarly, both linoleic (-0.497) and linolenic (-0.443) acids also showed a negative correlation with erucic acid. As a whole, BARI Sarisha14, BARI Sarisha-15, Maghi, Sonali Sarisha, and Improved Tori could be selected as potential parents for a hybridization program to breed potential recombinant lines with higher oil content and healthier unsaturated oleic and linoleic fatty acids.
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Sumaya Parveen and Abidur Rahman
International Journal of Molecular Sciences ( MDPI ) 22 ( 14 ) 7749 2021年07月 [査読有り]
学術誌 共著・分担
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Rahman T, Shao M, Pahari S, Venglat P, Soolanayakanahally R, Qiu X, Rahman A, Tanino K
Dissecting the Roles of Cuticular Wax in Plant Resistance to Shoot Dehydration and Low-Temperature Stress in Arabidopsis ( International Journal of Molecular Science ) 22 ( 4 ) 1554 2021年02月 [査読有り]
学術誌 共著・分担
Cuticular waxes are a mixture of hydrophobic very-long-chain fatty acids and their derivatives accumulated in the plant cuticle. Most studies define the role of cuticular wax largely based on reducing nonstomatal water loss. The present study investigated the role of cuticular wax in reducing both low-temperature and dehydration stress in plants using Arabidopsis thaliana mutants and transgenic genotypes altered in the formation of cuticular wax. cer3-6, a known Arabidopsis wax-deficient mutant (with distinct reduction in aldehydes, n-alkanes, secondary n-alcohols, and ketones compared to wild type (WT)), was most sensitive to water loss, while dewax, a known wax overproducer (greater alkanes and ketones compared to WT), was more resistant to dehydration compared to WT. Furthermore, cold-acclimated cer3-6 froze at warmer temperatures, while cold-acclimated dewax displayed freezing exotherms at colder temperatures compared to WT. Gas Chromatography-Mass Spectroscopy (GC-MS) analysis identified a characteristic decrease in the accumulation of certain waxes (e.g., alkanes, alcohols) in Arabidopsis cuticles under cold acclimation, which was additionally reduced in cer3-6. Conversely, the dewax mutant showed a greater ability to accumulate waxes under cold acclimation. Fourier Transform Infrared Spectroscopy (FTIR) also supported observations in cuticular wax deposition under cold acclimation. Our data indicate cuticular alkane waxes along with alcohols and fatty acids can facilitate avoidance of both ice formation and leaf water loss under dehydration stress and are promising genetic targets of interest.
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Aux/IAA14 Regulates microRNA-Mediated Cold Stress Response in Arabidopsis Roots
Aslam M, Kenji S, Qin Y, Rahman A
International Journal of Molecular Sciences ( MDPI ) 21 ( 22 ) 8441 2020年11月 [査読有り]
学術誌 共著・分担
The phytohormone auxin and microRNA-mediated regulation of gene expressions are key regulators of plant growth and development at both optimal and under low-temperature stress conditions. However, the mechanistic link between microRNA and auxin in regulating plant cold stress response remains elusive. To better understand the role of microRNA (miR) in the crosstalk between auxin and cold stress responses, we took advantage of the mutants of Arabidopsis thaliana with altered response to auxin transport and signal. Screening of the mutants for root growth recovery after cold stress at 4 °C revealed that the auxin signaling mutant, solitary root 1 (slr1; mutation in Aux/IAA14), shows a hypersensitive response to cold stress. Genome-wide expression analysis of miRs in the wild-type and slr1 mutant roots using next-generation sequencing revealed 180 known and 71 novel cold-responsive microRNAs. Cold stress also increased the abundance of 26–31 nt small RNA population in slr1 compared with wild type. Comparative analysis of microRNA expression shows significant differential expression of 13 known and 7 novel miRs in slr1 at 4 °C compared with wild type. Target gene expression analysis of the members from one potential candidate miR, miR169, revealed the possible involvement of miR169/NF-YA module in the Aux/IAA14-mediated cold stress response. Taken together, these results indicate that SLR/IAA14, a transcriptional repressor of auxin signaling, plays a crucial role in integrating miRs in auxin and cold responses.
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Rahman A, Kawamura Y, Maeshima M, Rahman A, Uemura M
Plant and Cell Physiology ( Oxford Academic ) 61 ( 4 ) 787 - 802 2020年01月 [査読有り]
学術誌 共著・分担
Aquaporins play a major role in plant water uptake at both optimal and environmentally stressed conditions. However, the functional specificity of aquaporins under cold remains obscure. To get a better insight to the role of aquaporins in cold acclimation and freezing tolerance, we took an integrated approach of physiology, transcript profiling and cell biology in Arabidopsis thaliana. Cold acclimation resulted in specific upregulation of PIP1;4 and PIP2;5 aquaporin (plasma membrane intrinsic proteins) expression, and immunoblotting analysis confirmed the increase in amount of PIP2;5 protein and total amount of PIPs during cold acclimation, suggesting that PIP2;5 plays a major role in tackling the cold milieu. Although single mutants of pip1;4 and pip2;5 or their double mutant showed no phenotypic changes in freezing tolerance, they were more sensitive in root elongation and cell survival response under freezing stress conditions compared with the wild type. Consistently, a single mutation in either PIP1;4 or PIP2;5 altered the expression of a number of aquaporins both at the transcriptional and translational levels. Collectively, our results suggest that aquaporin members including PIP1;4 and PIP2;5 function in concert to regulate cold acclimation and freezing tolerance responses.
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Li P, Yu Q, Xu G, Xu C, Qi S, Wang H, Zhong F, Baskin TI, Rahman A, Wu S
Current Biology 28 2777 - 2786 2018年09月 [査読有り]
国際的学術誌 共著・分担
The Casparian strip in the root endodermis forms an apoplastic barrier between vascular tissues and outer ground tissues to enforce selective absorption of water and nutrients. Because of its cell-type specificity, the presence of a Casparian strip is used as a marker for a functional endodermis. Here, we examine the minimal regulators required for reprograming non-endodermal cells to build a functional Casparian strip. We demonstrate that the transcription factor SHORT-ROOT (SHR) serves as a master regulator and promotes Casparian strip formation through two independent activities: inducing the expression of essential Casparian strip enzymes via MYB36 and directing the subcellular localization of Casparian strip formation via SCARECROW (SCR). However, this hierarchical signaling cascade still needs SHR-independent small peptides, derived from the stele, to eventually build a functional Casparian strip in non-endodermal cells.
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Li P, Yang M, Chang J, Wu J, Zhong F, Rahman A, Qin H, Wu S
Frontiers in Plant Science 9 ( 832 ) 1 - 15 2018年06月 [査読有り]
国際的学術誌 共著・分担
Casparian strip (CS) is an impregnation of endodermal cell wall, forming an apoplastic diffusion barrier which forces the symplastic and selective transport of nutrients across endodermis. This extracellular structure can be found in the roots of all higher plants and is thought to provide the protection of vascular tissues. In Arabidopsis, a genetic toolbox regulating the formation of Casparian strips has emerged recently. However, Arabidopsis has the stereotypical root which is much simpler than most other plant species. To understand the Casparian strip formation in a more complex root system, we examined CS regulatory pathways in tomato. Our results reveal a spatiotemporally conserved expression pattern of most essential components of CS machinery in tomato. Further functional analyses verify the role of homologous CS genes in the Casparian strip formation in tomato, indicating the functional conservation of CS regulatory cascade in tomato.
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Nakasone, A, Fujiwara, M, Fukao, Y, Biswas KK, Rahman A, Kawai-Yamada, M, Narumi I, Uchimiya H, and Oono Y
Plant Physiology 160 ( 1 ) 93 - 105 2012年05月 [査読有り]
国際的学術誌 共著・分担
Previously, a dysfunction of the SMALL ACIDIC PROTEIN1 (SMAP1) gene was identified as the cause of the anti-auxin resistant1 (aar1) mutant of Arabidopsis (Arabidopsis thaliana). However, the exact mechanism by which SMAP1 functions in auxin signaling remains unknown. Here, we demonstrate that SMAP1 is required for normal plant growth and development and the root response to indole-3-acetic acid or methyl jasmonate in the auxin resistant1 (axr1) mutation background. Deletion analysis and green fluorescent protein/glutathione S-transferase pull-down assays showed that SMAP1 physically interacts with the CONSTITUTIVE PHOTOMORPHOGENIC9 SIGNALOSOME (CSN) via the SMAP1 F/D region. The extremely dwarf phenotype of the aar1-1 csn5a-1 double mutant confirms the functional role of SMAP1 in plant growth and development under limiting CSN functionality.
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Shootward and rootward: peak terminology for plant polarity.
Baskin TI, Peret B, Baluška F, Benfey PN, Bennett M, Forde BG, Gilroy S, Helariutta Y, Hepler PK, Leyser O, Masson PH, Muday GK, Murphy AS, Poethig S, Rahman A, Roberts K, Scheres B, Sharp RE, and Somerville C
Trends in Plant Science 15 ( 11 ) 593 - 594 2010年10月 [査読有り]
学術誌 共著・分担
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PINOID kinase regulates root gravitropism through modulation of PIN2-dependent basipetal transport in Arabidopsis thaliana.
Sukumar P. Edwards KS, Rahman A, DeLong A, Muday GK
Plant Physiol ( 150 ) 722 - 735 2009年04月
学術誌 共著・分担
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Xu S, Rahman A, Baskin TI, Kieber JJ
Plant Cell 20 ( 11 ) 3065 - 3079 2008年04月 [査読有り]
学術誌 共著・分担
The plant cell wall is a dynamic structure that changes in response to developmental and environmental cues through poorly understood signaling pathways. We identified two Leu-rich repeat receptor-like kinases in Arabidopsis thaliana that play a role in regulating cell wall function. Mutations in these FEI1 and FEI2 genes (named for the Chinese word for fat) disrupt anisotropic expansion and the synthesis of cell wall polymers and act additively with inhibitors or mutations disrupting cellulose biosynthesis. While FEI1 is an active protein kinase, a kinase-inactive version of FEI1 was able to fully complement the fei1 fei2 mutant. The expansion defect in fei1 fei2 roots was suppressed by inhibition of 1-aminocyclopropane-1-carboxylic acid (ACC) synthase, an enzyme that converts Ado-Met to ACC in ethylene biosynthesis, but not by disruption of the ethylene response pathway. Furthermore, the FEI proteins interact directly with ACC synthase.
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Okamoto T, Tsurumi S, Shibasaki K, Obana Y, Takaji H, Oono Y, Rahman A
Plant Physiol. 146 ( 4 ) 1651 - 1662 2008年04月
学術誌 共著・分担
We investigated the role of ethylene and auxin in regulating the growth and morphology of roots during mechanical impedance by developing a new growing system and using the model plant Arabidopsis (Arabidopsis thaliana). The Arabidopsis seedlings grown horizontally on a dialysis membrane-covered agar plate encountered adequate mechanical impedance as the roots showed characteristic ethylene phenotypes: 2-fold reduction in root growth, increase in root diameter, decrease in cell elongation, and ectopic root hair formation. The root phenotype characterization of various mutants having altered response to ethylene biosynthesis or signaling, the effect of ethylene inhibitors on mechanically impeded roots, and transcription profiling of the ethylene-responsive genes led us to conclude that enhanced ethylene response plays a primary role in changing root morphology and development during mechanical impedance.
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Genetic Characterization of Mutants Resistant to the Antiauxin p-chlorophenoxyisobutyric Acid (PCIB) Reveals that AAR3, a Gene Encoding DCN1-Like Protein, regulates responses to the synthetic auxin 2,4-dichlorophenoxyacetic acid in Arabidopsis roots.
Biswas KK, Ooura C, Higuchi K, Miyazaki Y, Nguyen VV, Rahman A, Uchimiya H, Kiyosue T, Koshiba T, Tanaka A, Narumi I, Oono Y
Plant Physiology ( 145 ) 773 - 785 2007年11月 [査読有り]
学術誌 共著・分担
To isolate novel auxin-responsive mutants in Arabidopsis (Arabidopsis thaliana), we screened mutants for root growth resistance to a putative antiauxin, p-chlorophenoxyisobutyric acid (PCIB), which inhibits auxin action by interfering the upstream auxin-signaling events. Eleven PCIB-resistant mutants were obtained. Genetic mapping indicates that the mutations are located in at least five independent loci, including two known auxin-related loci, TRANSPORT INHIBITOR RESPONSE1 and Arabidopsis CULLIN1. antiauxin-resistant mutants (aars) aar3-1, aar4, and aar5 were also resistant to 2,4-dichlorophenoxyacetic acid as shown by a root growth assay. Positional cloning of aar3-1 revealed that the AAR3 gene encodes a protein with a domain of unknown function (DUF298), which has not previously been implicated in auxin signaling. The protein has a putative nuclear localization signal and shares homology with the DEFECTIVE IN CULLIN NEDDYLATION-1 protein through the DUF298 domain.
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Virus-induced gene silencing of P23k in barley leaf reveals morphological changes involved in secondary wall formation
Oikawa A, Rahman A, Yamashita T, Taira H, Kidou S
Journal of Experimental Botany ( 58 ) 2617 - 2625 2007年07月 [査読有り]
学術誌 共著・分担
P23k is a monocot-unique protein that is highly expressed in the scutellum of germinating barley seed.The role of P23k in barley physiology remains unclear. Here, to elucidate its physiological function, BSMV-based virus-induced gene silencing (VIGS) of P23k in barley leaves was performed. Expression and localization analyses of P23k mRNA in barley leaves showed up-regulation of P23k transcript with increased photosynthetic activity and the localization of these transcripts to the vascular bundles and sclerenchyma, where secondary wall formation is most active. VIGS of the P23k gene led to abnormal leaf development, asymmetric orientation of main veins, and cracked leaf edges caused by mechanical weakness. In addition, histochemical analyses indicated that the distribution of P23k in leaves coincides with the distribution of cell wall polysaccharides. Considering these results together, it is proposed that P23k is involved in the synthesis of cell wall polysaccharides.
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Auxin, actin, and growth of the Arabidopsis thaliana primary root.
Rahman A, Bannigan A, Sulaiman W, Oono Y, Baskin TI
The Plant Journal 50 ( 3 ) 514 - 528 2007年05月 [査読有り]
学術誌 共著・分担
To understand how auxin regulates root growth, we quantified cell division and elemental elongation, and examined actin organization in the primary root of Arabidopsis thaliana. In treatments for 48 h that inhibited root elongation rate by 50%, we find that auxins and auxin-transport inhibitors can be divided into two classes based on their effects on cell division, elongation and actin organization. Indole acetic acid (IAA), 1-naphthalene acetic acid (NAA) and tri-iodobenzoic acid (TIBA) inhibit root growth primarily through reducing the length of the growth zone rather than the maximal rate of elemental elongation and they do not reduce cell production rate. These three compounds have little effect on the extent of filamentous actin, as imaged in living cells or by chemical fixation and immuno-cytochemistry, but tend to increase actin bundling. Our results show that IAA regulates the size of the root elongation zone whereas 2,4-D affects cell production and actin-dependent processes.
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Rahman A, Nakasone A, Chhun T, Ooura C, Biswas KK, Uchimiya H, Tsurumi S, Baskin TI, Tanaka A, Oono Y
Plant Journal 47 ( 5 ) 788 - 801 2006年05月 [査読有り]
学術誌 共著・分担
2,4-dichlorophenoxyacetic acid (2,4-D), a chemical analogue of indole-3-acetic acid (IAA) is believed to share a common response pathway. Here, we show that a mutant, antiauxin resistant1 (aar1), identified in a screen for resistance to the anti-auxin p-chlorophenoxy-isobutyric acid (PCIB), is resistant to 2,4-D, yet nevertheless responds like the wild-type to IAA and 1-napthaleneacetic acid in root elongation and lateral root induction assays. That the aar1 mutation alters 2,4-D responsiveness specifically was confirmed by analysis of GUS expression in the DR5:GUS and HS:AXR3NT-GUS backgrounds, as well as by real-time PCR quantification of IAA 11 expression. The two characterized aar1 alleles both harbor multi-gene deletions; however, 2,4-D responsiveness was restored by transformation with one of the genes SMAP1, which encodes a novel protein with unknown function.
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Structure-Function Analysis of the presumptive Arabidopsis Auxin Permease AUX1.
Swarup R, Kargul J, Marchant A, Zadik D, Rahman A, Mills R, Yemm A, May S, Williams L, Millner P, Tsurumi S, Moore I, Napier R, Kerr ID, Bennett MJ
Plant Cell 16 ( 11 ) 3069 - 3083 2004年10月 [査読有り]
学術誌 共著・分担
We have investigated the subcellular localization, the domain topology, and the amino acid residues that are critical for the function of the presumptive Arabidopsis thaliana auxin influx carrier AUX1. Biochemical fractionation experiments and confocal studies using an N-terminal yellow fluorescent protein (YFP) fusion observed that AUX1 colocalized with plasma membrane (PM) markers. Because of its PM localization, we were able to take advantage of the steep pH gradient that exists across the plant cell PM to investigate AUX1 topology using YFP as a pH-sensitive probe. The YFP-coding sequence was inserted in selected AUX1 hydrophilic loops to orient surface domains on either apoplastic or cytoplasmic faces of the PM based on the absence or presence of YFP fluorescence, respectively. We were able to demonstrate in conjunction with helix prediction programs that AUX1 represents a polytopic membrane protein composed of 11 transmembrane spanning domains.