scholarly journals The SUPPRESSOR of MAX2 1 (SMAX1)-Like SMXL6, SMXL7 and SMXL8 Act as Negative Regulators in Response to Drought Stress in Arabidopsis

2020 ◽  
Vol 61 (8) ◽  
pp. 1477-1492 ◽  
Author(s):  
Tao Yang ◽  
Yuke Lian ◽  
Jihong Kang ◽  
Zhiyuan Bian ◽  
Lijuan Xuan ◽  
...  
Keyword(s):  
Drought Stress ◽  
Genetic Manipulation ◽  
Anthocyanin Biosynthesis ◽  
Stomatal Closure ◽  
Drought Response ◽  
Plant Responses ◽  
Sequencing Analysis ◽  
Dependent Manner ◽  
Cuticular Permeability ◽  
Biochemical Analyses

Abstract Drought represents a major threat to crop growth and yields. Strigolactones (SLs) contribute to regulating shoot branching by targeting the SUPPRESSOR OF MORE AXILLARY GROWTH2 (MAX2)-LIKE6 (SMXL6), SMXL7 and SMXL8 for degradation in a MAX2-dependent manner in Arabidopsis. Although SLs are implicated in plant drought response, the functions of the SMXL6, 7 and 8 in the SL-regulated plant response to drought stress have remained unclear. Here, we performed transcriptomic, physiological and biochemical analyses of smxl6, 7, 8 and max2 plants to understand the basis for SMXL6/7/8-regulated drought response. We found that three D53 (DWARF53)-Like SMXL members, SMXL6, 7 and 8, are involved in drought response as the smxl6smxl7smxl8 triple mutants showed markedly enhanced drought tolerance compared to wild type (WT). The smxl6smxl7smxl8 plants exhibited decreased leaf stomatal index, cuticular permeability and water loss, and increased anthocyanin biosynthesis during dehydration. Moreover, smxl6smxl7smxl8 were hypersensitive to ABA-induced stomatal closure and ABA responsiveness during and after germination. In addition, RNA-sequencing analysis of the leaves of the D53-like smxl mutants, SL-response max2 mutant and WT plants under normal and dehydration conditions revealed an SMXL6/7/8-mediated network controlling plant adaptation to drought stress via many stress- and/or ABA-responsive and SL-related genes. These data further provide evidence for crosstalk between ABA- and SL-dependent signaling pathways in regulating plant responses to drought. Our results demonstrate that SMXL6, 7 and 8 are vital components of SL signaling and are negatively involved in drought responses, suggesting that genetic manipulation of SMXL6/7/8-dependent SL signaling may provide novel ways to improve drought resistance.

scholarly journals A MYB-related Transcription Factor from Sheepgrass, LcMYB2, Promotes Seed Germination and Root Growth under Drought Stress

2019 ◽  
Author(s):  
Pincang Zhao ◽  
Shenglin Hou ◽  
xiufang guo ◽  
Junting Jia ◽  
Weiguang Yang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Drought Stress ◽  
Seed Germination ◽  
Osmotic Stress ◽  
Root Growth ◽  
Genetic Manipulation ◽  
Marker Genes ◽  
Plant Responses ◽  
Adverse Conditions ◽  
Related Transcription Factor

Abstract Background Drought is one of the most serious factors limiting plant growth and production. Sheepgrass can adapt well to various adverse conditions, including drought. However, during germination, sheepgrass young seedlings are sensitive to these adverse conditions. Therefore, the adaptability of seedlings is very important for plant survival, especially in plants that inhabit grasslands or the construction of artificial grassland. Results In this study, we found a sheepgrass MYB-related transcription factor, LcMYB2 that is up-regulated by drought stress and returns to a basal level after rewatering. The expression of LcMYB2 was mainly induced by osmotic stress and was localized to the nucleus. Furthermore, we demonstrate that LcMYB2 promoted seed germination and root growth under drought and ABA treatments. Additionally, we confirmed that LcMYB2 can regulate LcDREB2 expression in sheepgrass by binding to its promoter, and it activates the expression of the osmotic stress marker genes AtDREB2A, AtLEA14 and AtP5CS1 by directly binding to their promoters in transgenic Arabidopsis. Conclusions Based on these results, we propose that LcMYB2 improves plant drought stress tolerance by increasing the accumulation of osmoprotectants and promoting root growth. Therefore, LcMYB2 plays pivotal roles in plant responses to drought stress and is an important candidate for genetic manipulation to create drought-resistant crops, especially during seed germination.

scholarly journals Infection with an asymptomatic virus in rice results in a delayed drought response

2020 ◽  
Vol 47 (3) ◽  
pp. 239 ◽  
Author(s):  
Jaymee R. Encabo ◽  
Reena Jesusa A. Macalalad-Cabral ◽  
Jerlie Mhay K. Matres ◽  
Sapphire Charlene Thea P. Coronejo ◽  
Gilda B. Jonson ◽  
...  
Keyword(s):  
Drought Stress ◽  
Abiotic Stresses ◽  
Water Status ◽  
Drought Response ◽  
Plant Responses ◽  
Leaf Rolling ◽  
Rice Tungro Spherical Virus ◽  
Biotic And Abiotic Stresses ◽  
Rice Plants ◽  
Increased Susceptibility

Infection of viruses in plants often modifies plant responses to biotic and abiotic stresses. In the present study we examined the effects of Rice tungro spherical virus (RTSV) infection on drought response in rice. RTSV infection delayed the onset of leaf rolling by 1–2 days. During the delay in drought response, plants infected with RTSV showed higher stomatal conductance and less negative leaf water potential under drought than those of uninfected plants, indicating that RTSV-infected leaves were more hydrated. Other growth and physiological traits of plants under drought were not altered by infection with RTSV. An expression analysis of genes for drought response-related transcription factors showed that the expression of OsNAC6 and OsDREB2a was less activated by drought in RTSV-infected plants than in uninfected plants, further suggesting improved water status of the plants due to RTSV infection. RTSV accumulated more in plants under drought than in well-watered plants, indicating the increased susceptibility of rice plants to RTSV infection by drought. Collectively, these results indicated that infection with RTSV can transiently mitigate the influence of drought stress on rice plants by increasing leaf hydration, while drought increased the susceptibility of rice plants to RTSV.

scholarly journals A MYB-related Transcription Factor from Sheepgrass, LcMYB2, Promotes Seed Germination and Root Growth under Drought Stress

2019 ◽  
Author(s):  
xiufang guo ◽  
Pincang Zhao ◽  
Shenglin Hou ◽  
Junting Jia ◽  
Weiguang Yang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Drought Stress ◽  
Seed Germination ◽  
Osmotic Stress ◽  
Root Growth ◽  
Genetic Manipulation ◽  
Marker Genes ◽  
Plant Responses ◽  
Adverse Conditions ◽  
Related Transcription Factor

Abstract Background Drought is one of the most serious factors limiting plant growth and production. Sheepgrass can adapt well to various adverse conditions, including drought. However, during germination, sheepgrass young seedlings are sensitive to these adverse conditions. Therefore, the adaptability of seedlings is very important for plant survival, especially in plants that inhabit grasslands or the construction of artificial grassland. Results In this study, we found a sheepgrass MYB-related transcription factor, LcMYB2 that is up-regulated by drought stress and returns to a basal level after rewatering. The expression of LcMYB2 was mainly induced by osmotic stress and was localized to the nucleus. Furthermore, we demonstrate that LcMYB2 promoted seed germination and root growth under drought and ABA treatments. Additionally, we confirmed that LcMYB2 can regulate LcDREB2 expression in sheepgrass by binding to its promoter, and it activates the expression of the osmotic stress marker genes AtDREB2A, AtLEA14 and AtP5CS1 by directly binding to their promoters in transgenic Arabidopsis. Conclusions Based on these results, we propose that LcMYB2 improves plant drought stress tolerance by increasing the accumulation of osmoprotectants and promoting root growth. Therefore, LcMYB2 plays pivotal roles in plant responses to drought stress and is an important candidate for genetic manipulation to create drought-resistant crops, especially during seed germination.

scholarly journals Morphological and Physiological Plant Responses to Drought Stress inThymus citriodorus

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Zdzislaw Attila Tátrai ◽  
Rabab Sanoubar ◽  
Zsuzsanna Pluhár ◽  
Silvia Mancarella ◽  
Francesco Orsini ◽  
...  
Keyword(s):  
Drought Stress ◽  
Plant Growth ◽  
Water Use ◽  
Water Uptake ◽  
Stomatal Closure ◽  
Water Shortage ◽  
Root Water Uptake ◽  
Absorption Capacity ◽  
Plant Responses ◽  
Mild Stress

Water availability is considered as a determinant factor that affects plant growth. The commercial medicinal values of an aromatic plant rely on the presence of secondary metabolites that are affected under water shortage. Two-year-oldThymus citriodorusplants were subjected to different polyethylene glycol (PEG-6000) levels (0, 2%, and 4%) under greenhouse condition. PEG treatment lasted for 15 days. Thyme plant showed a morphological drought avoidance mechanism by maintaining the root system development through shoot fresh weight reduction resulting in promoted root absorption capacity and sustained plant growth. Moreover, stressed plants were able to maintain water use efficiency and root : shoot ratio suggesting a strong relation between root water uptake and water use saving strategies. Furthermore, thyme plants reduced tissue dehydration through stomatal closure and improved root water uptake. Content of volatile oil constituents of geraniol and diisobutyl phthalate increased upon drought stress while pseudophytol was reduced. Unexpectedly, thymol was not reported as a main oil element under either control or mild stress condition, while it was increased upon high drought stress in measure of 4.4%. Finally, carvacrol significantly accumulated under high drought stress (+31.7%) as compared to control plants.

scholarly journals The Cyclophilin ROC3 Regulates ABA-Induced Stomatal Closure and the Drought Stress Response of Arabidopsis thaliana

2021 ◽  
Vol 12 ◽  
Author(s):  
Huiping Liu ◽  
Jianlin Shen ◽  
Chao Yuan ◽  
Dongxue Lu ◽  
Biswa R. Acharya ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Drought Stress ◽  
Stress Response ◽  
Stomatal Closure ◽  
Anion Channel ◽  
Crop Productivity ◽  
Drought Response ◽  
Wild Type ◽  
Ros Homeostasis ◽  
Ros Accumulation

Drought causes a major constraint on plant growth, development, and crop productivity. Drought stress enhances the synthesis and mobilization of the phytohormone abscisic acid (ABA). Enhanced cellular levels of ABA promote the production of reactive oxygen species (ROS), which in turn induce anion channel activity in guard cells that consequently leads to stomatal closure. Although Cyclophilins (CYPs) are known to participate in the biotic stress response, their involvement in guard cell ABA signaling and the drought response remains to be established. The Arabidopsis thaliana gene ROC3 encodes a CYP. Arabidopsis roc3 T-DNA mutants showed a reduced level of ABA-activated S-type anion currents, and stomatal closure than wild type (WT). Also, roc3 mutants exhibited rapid loss of water in leaf than wild type. Two complementation lines of roc3 mutants showed similar stomatal response to ABA as observed for WT. Both complementation lines also showed similar water loss as WT by leaf detached assay. Biochemical assay suggested that ROC3 positively regulates ROS accumulation by inhibiting catalase activity. In response to ABA treatment or drought stress, roc3 mutant show down regulation of a number of stress responsive genes. All findings indicate that ROC3 positively regulates ABA-induced stomatal closure and the drought response by regulating ROS homeostasis and the expression of various stress-activated genes.

scholarly journals Reproductive Stage Drought Tolerance in Wheat: Importance of Stomatal Conductance and Plant Growth Regulators

Genes ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1742
Author(s):  
Olive Onyemaobi ◽  
Harriet Sangma ◽  
Gagan Garg ◽  
Xiaomei Wallace ◽  
Sue Kleven ◽  
...  
Keyword(s):  
Drought Stress ◽  
Stomatal Conductance ◽  
Drought Tolerance ◽  
Stomatal Closure ◽  
Protein Translation ◽  
Water Levels ◽  
Drought Response ◽  
Flag Leaves ◽  
Tolerant Line ◽  
Wheat Lines

Drought stress requires plants to adjust their water balance to maintain tissue water levels. Isohydric plants (‘water-savers’) typically achieve this through stomatal closure, while anisohydric plants (‘water-wasters’) use osmotic adjustment and maintain stomatal conductance. Isohydry or anisohydry allows plant species to adapt to different environments. In this paper we show that both mechanisms occur in bread wheat (Triticum aestivum L.). Wheat lines with reproductive drought-tolerance delay stomatal closure and are temporarily anisohydric, before closing stomata and become isohydric at higher threshold levels of drought stress. Drought-sensitive wheat is isohydric from the start of the drought treatment. The capacity of the drought-tolerant line to maintain stomatal conductance correlates with repression of ABA synthesis in spikes and flag leaves. Gene expression profiling revealed major differences in the drought response in spikes and flag leaves of both wheat lines. While the isohydric drought-sensitive line enters a passive growth mode (arrest of photosynthesis, protein translation), the tolerant line mounts a stronger stress defence response (ROS protection, LEA proteins, cuticle synthesis). The drought response of the tolerant line is characterised by a strong response in the spike, displaying enrichment of genes involved in auxin, cytokinin and ethylene metabolism/signalling. While isohydry may offer advantages for longer term drought stress, anisohydry may be more beneficial when drought stress occurs during the critical stages of wheat spike development, ultimately improving grain yield.

scholarly journals A MYB-related Transcription Factor from Sheepgrass, LcMYB2, Promotes Seed Germination and Root Growth under Drought Stress

2019 ◽  
Author(s):  
Pincang Zhao ◽  
Shenglin Hou ◽  
xiufang guo ◽  
Junting Jia ◽  
Weiguang Yang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Drought Stress ◽  
Seed Germination ◽  
Osmotic Stress ◽  
Root Growth ◽  
Genetic Manipulation ◽  
Marker Genes ◽  
Plant Responses ◽  
Adverse Conditions ◽  
Related Transcription Factor

Abstract Background Drought is one of the most serious factors limiting plant growth and production. Sheepgrass can adapt well to various adverse conditions, including drought. However, during germination, sheepgrass young seedlings are sensitive to these adverse conditions. Therefore, the adaptability of seedlings is very important for plant survival, especially in plants that inhabit grasslands or the construction of artificial grassland. Results In this study, we found a sheepgrass MYB-related transcription factor, LcMYB2 that is up-regulated by drought stress and returns to a basal level after rewatering. The expression of LcMYB2 was mainly induced by osmotic stress and was localized to the nucleus. Furthermore, we demonstrate that LcMYB2 promoted seed germination and root growth under drought and ABA treatments. Additionally, we confirmed that LcMYB2 can regulate LcDREB2 expression in sheepgrass by binding to its promoter, and it activates the expression of the osmotic stress marker genes AtDREB2A, AtLEA14 and AtP5CS1 by directly binding to their promoters in transgenic Arabidopsis. Conclusions Based on these results, we propose that LcMYB2 improves plant drought stress tolerance by increasing the accumulation of osmoprotectants and promoting root growth. Therefore, LcMYB2 plays pivotal roles in plant responses to drought stress and is an important candidate for genetic manipulation to create drought-resistant crops, especially during seed germination.

scholarly journals A MYB-related transcription factor from sheepgrass, LcMYB2, promotes seed germination and root growth under drought stress

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Pincang Zhao ◽  
Shenglin Hou ◽  
Xiufang Guo ◽  
Junting Jia ◽  
Weiguang Yang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Drought Stress ◽  
Seed Germination ◽  
Osmotic Stress ◽  
Root Growth ◽  
Genetic Manipulation ◽  
Marker Genes ◽  
Plant Responses ◽  
Adverse Conditions ◽  
Related Transcription Factor

Abstract Background Drought is one of the most serious factors limiting plant growth and production. Sheepgrass can adapt well to various adverse conditions, including drought. However, during germination, sheepgrass young seedlings are sensitive to these adverse conditions. Therefore, the adaptability of seedlings is very important for plant survival, especially in plants that inhabit grasslands or the construction of artificial grassland. Results In this study, we found a sheepgrass MYB-related transcription factor, LcMYB2 that is up-regulated by drought stress and returns to a basal level after rewatering. The expression of LcMYB2 was mainly induced by osmotic stress and was localized to the nucleus. Furthermore, we demonstrate that LcMYB2 promoted seed germination and root growth under drought and ABA treatments. Additionally, we confirmed that LcMYB2 can regulate LcDREB2 expression in sheepgrass by binding to its promoter, and it activates the expression of the osmotic stress marker genes AtDREB2A, AtLEA14 and AtP5CS1 by directly binding to their promoters in transgenic Arabidopsis. Conclusions Based on these results, we propose that LcMYB2 improves plant drought stress tolerance by increasing the accumulation of osmoprotectants and promoting root growth. Therefore, LcMYB2 plays pivotal roles in plant responses to drought stress and is an important candidate for genetic manipulation to create drought-resistant crops, especially during seed germination.

scholarly journals (319) Mycorrhizal Symbiosis and Response of Sorghum Plants to Combined Drought and Salt Stresses

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1037C-1037
Author(s):  
Robert Augé ◽  
Keunho Cho ◽  
Jean Stutz ◽  
Heather Toler
Keyword(s):  
Salt Stress ◽  
Drought Stress ◽  
Host Resistance ◽  
Glomus Intraradices ◽  
Stomatal Closure ◽  
Soil Water Potential ◽  
Am Fungi ◽  
Nacl Stress ◽  
Mycorrhizal Symbiosis ◽  
Drought Response

Colonization of roots by arbuscular mycorrhizal (AM) fungi can increase host resistance to drought stress, although the effect is unpredictable. Since AM symbiosis also frequently increases host resistance to salt stress, and since drought and salt stress are often linked in drying soils, we speculated that the AM influence on plant drought response may be linked to AM influence on salt stress. We tested the hypothesis that AM-induced effects on drought responses would be more pronounced when plants of comparable size are exposed to drought in salinized soils. In two greenhouse experiments, several water relations characteristics were measured in sorghum plants colonized by Glomus intraradices, Gigaspora margarita, or a mixture of AM species during a sustained drought following exposure to salt treatments (NaCl stress, osmotic stress, or soil leaching). The presence of excess salt in soils widened the difference in drought responses between AM and non-AM plants in just two instances: days needed for plants to reach stomatal closure, and promotion of stomatal conductance. In other instances, the addition of salt tended to nullify an AM-induced change in drought response; e.g., an AM effect on the decline in leaf or soil water potential required to cause stomatal closure disappeared when soils were salinized. Our findings confirm that AM fungi can alter host response to drought but do not lend much support to the idea that AM-induced salt resistance might help explain why AM plants can be more resilient to drought stress than their non-AM counterparts.

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