scholarly journals AtSK11 and AtSK12 Mediate the Mild Osmotic Stress-Induced Root Growth Response in Arabidopsis

2020 ◽  
Vol 21 (11) ◽  
pp. 3991 ◽  
Author(s):  
Long Dong ◽  
Zhixin Wang ◽  
Jing Liu ◽  
Xuelu Wang
Keyword(s):  
Arabidopsis Thaliana ◽  
Transcription Factor ◽  
Plant Growth ◽  
Osmotic Stress ◽  
Root Growth ◽  
Growth Response ◽  
Glycogen Synthase ◽  
Plant Root ◽  
Bhlh Transcription Factor ◽  
Mild Stress

Although most osmotic stresses are harmful to plant growth and development, certain drought- or polyethylene glycol (PEG)-induced mild osmotic stresses promote plant root growth. The underlying regulatory mechanisms of this response remain elusive. Here, we report that the GLYCOGEN SYNTHASE KINASE 3 (GSK3) genes ARABIDOPSIS THALIANA SHAGGY-RELATED KINASE 11 (AtSK11) (AT5G26751) and AtSK12 (AT3G05840) are involved in the mild osmotic stress (−0.4 MPa) response in Arabidopsis thaliana. When grown on plant medium infused with different concentrations of PEG to mimic osmotic stress, both wild-type (WT) and atsk11atsk12 plants showed stimulated root growth under mild osmotic stress (−0.4 MPa) but repressed root growth under relatively strong osmotic stress (−0.5, −0.6, −0.7 MPa) as compared to the mock condition (−0.25 MPa). The root growth stimulation of atsk11atsk12 was more sensitive to −0.4 MPa treatment than was that of WT, indicating that AtSK11 and AtSK12 inhibit the mild stress-induced root growth response. RNA-seq analysis of WT and atsk11atsk12 plants under three water potentials (−0.25 MPa, −0.4 MPa, −0.6 MPa) revealed 10 differentially expressed candidate genes mainly involved in cell wall homeostasis, which were regulated by AtSK11 and AtSK12 to regulate root growth in response to the mild stress condition (−0.4 MPa). Promoter motif and transcription factor binding analyses suggested that the basic helix-loop-helix (bHLH) transcription factor bHLH69/LJRHL1-LIKE 2 (LRL2) may directly regulate the expression of most −0.4 MPa-responsive genes. These findings indicate that mild osmotic stress (−0.4 MPa) promotes plant growth and that the GSK3 family kinase genes AtSK11 and AtSK12 play a negative role in the induction of root growth in response to mild osmotic stress.

scholarly journals Altered Root Growth, Auxin Metabolism and Distribution in Arabidopsis thaliana Exposed to Salt and Osmotic Stress

2021 ◽  
Vol 22 (15) ◽  
pp. 7993
Author(s):  
Ana Smolko ◽  
Nataša Bauer ◽  
Iva Pavlović ◽  
Aleš Pěnčík ◽  
Ondřej Novák ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Salt Stress ◽  
Osmotic Stress ◽  
Root Growth ◽  
Plant Root ◽  
Stress Factors ◽  
Quiescent Center ◽  
Gene Expressions ◽  
Auxin Distribution ◽  
Salt And Osmotic Stress

Salt and osmotic stress are the main abiotic stress factors affecting plant root growth and architecture. We investigated the effect of salt (100 mM NaCl) and osmotic (200 mM mannitol) stress on the auxin metabolome by UHPLC-MS/MS, auxin distribution by confocal microscopy, and transcript levels of selected genes by qRT-PCR in Arabidopsis thaliana ecotype Columbia-0 (Col-0) and DR5rev::GFP (DR5) line. During long-term stress (13 days), a stability of the auxin metabolome and a tendency to increase indole-3-acetic acid (IAA) were observed, especially during salt stress. Short-term stress (3 h) caused significant changes in the auxin metabolome, especially NaCl treatment resulted in a significant reduction of IAA. The data derived from auxin profiling were consistent with gene expressions showing the most striking changes in the transcripts of YUC, GH3, and UGT transcripts, suggesting disruption of auxin biosynthesis, but especially in the processes of amide and ester conjugation. These data were consistent with the auxin distribution observed in the DR5 line. Moreover, NaCl treatment caused a redistribution of auxin signals from the quiescent center and the inner layers of the root cap to the epidermal and cortical cells of the root elongation zone. The distribution of PIN proteins was also disrupted by salt stress; in particular, PIN2 was suppressed, even after 5 min of treatment. Based on our results, the DR5 line was more sensitive to the applied stresses than Col-0, although both lines showed similar trends in root morphology, as well as transcriptome and metabolome parameters under stress conditions.

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.

Fish effluents promote root growth and suppress fungal diseases in tomato transplants

2015 ◽  
Vol 95 (2) ◽  
pp. 427-436 ◽  
Author(s):  
Valérie Gravel ◽  
Martine Dorais ◽  
Dipa Dey ◽  
Grant Vandenberg
Keyword(s):  
Plant Growth ◽  
Root Growth ◽  
Plant Root ◽  
Fish Farming ◽  
Pythium Ultimum ◽  
Fungal Diseases ◽  
Growth Promoter ◽  
Soil Suppressiveness ◽  
Nutrient Value

Gravel, V., Dorais, M., Dey, D. and Vandenberg, G. 2015. Fish effluents promote root growth and suppress fungal diseases in tomato transplants. Can. J. Plant Sci. 95: 427–436. Aquaculture systems generate large amounts of wastes which may constitute a beneficial amendment for horticultural crop in terms of nutrients, plant growth promoter and disease suppressiveness. This study aimed to determine (1) the nutrient value of rainbow trout farming effluents coming from two feed regimes and (2) the plant growth and disease suppressiveness effects of those fish farming effluents on tomato transplants. The effluent sludge from Skretting Orient™ (SO) had a higher content of P (38 vs. 32 mg L−1), K (23 vs. 11 mg L−1), N (19 vs. to 11 mg NO3 L−1; 186 vs. 123 mg NH4 L−1), and a higher NO3:NH4 ratio (1:9 vs. 1:13) compared with the Martin Classic (MC), while MC was richer in Mg (42 vs. 24 mg L−1) and Ca (217 vs. 169 mg L−1). For the first trial, a stimulating effect of the fish effluent was observed on plant height, leaf area and root dry biomass, while only the root biomass was increased during the second trial. Fish sludge was rich in microorganisms (97 and 142 µg fluorescein h−1 mL−1 for SO and MC, respectively) and their ability to suppress Pythium ultimum Trow and Fusarium oxysporum f.sp. lycopersici (Sacc.) Snyder & Hansen was observed. Both crude fish effluents reduced in vitro mycelial growth of P. ultimum and F. oxysporum, by 100 and 32%, respectively, while MC effluents showed a higher inhibition against F. oxysporum. When fish effluents were sterilized by filtration or autoclaving, lower in vitro inhibition of P. ultimum and F. oxysporum was observed. Mixed fish effluents reduced tomato plant root colonization by P. ultimum (by up to 5.7-fold) and F. oxysporum (by up to 2.1-fold). These results showed that fish effluent can be used as soil amendments to promote plant growth and increase soil suppressiveness, which in turn can prevent soil-borne diseases.

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 Plantibacter flavus, Curtobacterium herbarum, Paenibacillus taichungensis, and Rhizobium selenitireducens Endophytes Provide Host-Specific Growth Promotion of Arabidopsis thaliana, Basil, Lettuce, and Bok Choy Plants

2019 ◽  
Vol 85 (19) ◽  
Author(s):  
Evan Mayer ◽  
Patricia Dörr de Quadros ◽  
Roberta Fulthorpe
Keyword(s):  
Arabidopsis Thaliana ◽  
Plant Growth ◽  
Root Growth ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
Plant Growth Promoting Bacteria ◽  
Bacterial Endophytes ◽  
Content Type ◽  
Plant Growth Promoting ◽  
Growth Promoting

ABSTRACT A collection of bacterial endophytes isolated from stem tissues of plants growing in soils highly contaminated with petroleum hydrocarbons were screened for plant growth-promoting capabilities. Twenty-seven endophytic isolates significantly improved the growth of Arabidopsis thaliana plants in comparison to that of uninoculated control plants. The five most beneficial isolates, one strain each of Curtobacterium herbarum, Paenibacillus taichungensis, and Rhizobium selenitireducens and two strains of Plantibacter flavus were further examined for growth promotion in Arabidopsis, lettuce, basil, and bok choy plants. Host-specific plant growth promotion was observed when plants were inoculated with the five bacterial strains. P. flavus strain M251 increased the total biomass and total root length of Arabidopsis plants by 4.7 and 5.8 times, respectively, over that of control plants and improved lettuce and basil root growth, while P. flavus strain M259 promoted Arabidopsis shoot and root growth, lettuce and basil root growth, and bok choy shoot growth. A genome comparison between P. flavus strains M251 and M259 showed that both genomes contain up to 70 actinobacterial putative plant-associated genes and genes involved in known plant-beneficial pathways, such as those for auxin and cytokinin biosynthesis and 1-aminocyclopropane-1-carboxylate deaminase production. This study provides evidence of direct plant growth promotion by Plantibacter flavus. IMPORTANCE The discovery of new plant growth-promoting bacteria is necessary for the continued development of biofertilizers, which are environmentally friendly and cost-efficient alternatives to conventional chemical fertilizers. Biofertilizer effects on plant growth can be inconsistent due to the complexity of plant-microbe interactions, as the same bacteria can be beneficial to the growth of some plant species and neutral or detrimental to others. We examined a set of bacterial endophytes isolated from plants growing in a unique petroleum-contaminated environment to discover plant growth-promoting bacteria. We show that strains of Plantibacter flavus exhibit strain-specific plant growth-promoting effects on four different plant species.

scholarly journals bHLH transcription factor bHLH115 regulates iron homeostasis in Arabidopsis thaliana

2017 ◽  
Vol 68 (7) ◽  
pp. 1743-1755 ◽  
Author(s):  
Gang Liang ◽  
Huimin Zhang ◽  
Xiaoli Li ◽  
Qin Ai ◽  
Diqiu Yu
Keyword(s):  
Arabidopsis Thaliana ◽  
Transcription Factor ◽  
Iron Homeostasis ◽  
Bhlh Transcription Factor
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