Microbe-induced drought tolerance by ABA-mediated root architecture and epigenetic reprograming
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ABSTRACT:
SUBMITTER: khairiah, m alwutayd
PROVIDER: S-SCDT-10_15252-EMBR_202256754 | biostudies-other |
REPOSITORIES: biostudies-other
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Project description:The WRKY transcription factors (TFs) are one of the largest families of TFs in plants and play multiple roles in plant development and stress response. In the present study, GmWRKY16 encoding a WRKY transcription factor in soybean was functionally characterized in Arabidopsis. GmWRKY16 is a nuclear protein that contains a highly conserved WRKY domain and a C2H2 zinc-finger structure, and has the characteristics of transcriptional activation ability, presenting a constitutive expression pattern with relative expression levels of over fourfold in the old leaves, flowers, seeds and roots of soybean. The results of quantitative real time polymerase chain reaction (qRT-PCR) showed that GmWRKY16 could be induced by salt, alkali, ABA, drought and PEG-6000. As compared with the control, overexpression of GmWRKY16 in Arabidopsis increased the seed germination rate and root growth of seedlings in transgenic lines under higher concentrations of mannitol, NaCl and ABA. In the meantime, GmWRKY16 transgenic lines showed over 75% survival rate after rehydration and enhanced Arabidopsis tolerance to salt and drought with higher proline and lower MDA accumulation, less water loss of the detached leaves, and accumulated more endogenous ABA than the control under stress conditions. Further studies showed that AtWRKY8, KIN1, and RD29A were induced in GmWRKY16 transgenic plants under NaCl treatment. The expressions of the ABA biosynthesis gene (NCED3), signaling genes (ABI1, ABI2, ABI4, and ABI5), responsive genes (RD29A, COR15A, COR15B, and RD22) and stress-related marker genes (KIN1, LEA14, LEA76, and CER3) were regulated in transgenic lines under drought stress. In summary, these results suggest that GmWRKY16 as a WRKY TF may promote tolerance to drought and salt stresses through an ABA-mediated pathway.
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Project description:In this study, we investigated the function of OsAAI1 in yield and drought tolerance by constructing overexpression line OE-OsAAI1 and mutant line osaai1. Bioinformatics analysis showed that the AAI gene-OsAAI1- belongs to the HPS_like subfamily of the AAI_LTSS superfamily, and OsAAI1 was localized in the nucleus. The expression of OsAAI1 was significantly induced by ABA and drought stress. OsAAI1 overexpression (OE19) significantly increased, and gene mutant (osaai1-1) repressed plant height, primary root length, lateral root number, grain size and yield in rice. Moreover, physiological and biochemical analyses showed that osaai1 was sensitive to drought stress, while OE19 enhanced the drought tolerance in rice. DAB and NBT staining revealed that under drought treatment, osaai1 accumulated a large amount of ROS compared with the wild type, while OE19 accumulated the least, and CAT, APX, GPX, GR activities were higher in OE19 and lower in osaai1, suggesting that OE19 improves rice tolerance to drought stress by enhancing ROS scavenging ability. OE19 also induce the expression of ABA-mediated regulatory pathway genes and enhance accumulation of ABA content in rice seedling. Predictably, OE19 displayed enhanced sensitivity to ABA, and ROS accumulation was significantly higher than in wild type and osaai1 under 3 µM ABA treatment. Thus, these results suggest that OsAAI1 is a positive regulator of rice yield and drought tolerance dependent on the ABA-mediated regulatory and ROS scavenging pathway.
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