OsMLP423 Is a Positive Regulator of Tolerance to Drought and Salt Stresses in Rice

Abstract

Rice (Oryza sativa L.) is one of the main food crops for human survival, and its yield is often restricted by abiotic stresses. Drought and soil salinity are among the most damaging abiotic stresses affecting today’s agriculture. Given the importance of abscisic acid (ABA) in plant growth and abiotic stress responses, it is very important to identify new genes involved in ABA signal transduction. We screened a drought-inducing gene containing about 158 amino acid residues from the transcriptome library of rice exposed to drought treatment, and we found ABA-related cis-acting elements and multiple drought-stress-related cis-acting elements in its promoter sequence. The results of real-time PCR showed that OsMLP423 was strongly induced by drought and salt stresses. The physiological and biochemical phenotype analysis of transgenic plants confirmed that overexpression of OsMLP423 enhanced the tolerance to drought and salt stresses in rice. The expression of OsMLP423-GFP fusion protein indicated that OsMLP423 was located in both the cell membrane system and nucleus. Compared with the wild type, the overexpressed OsMLP423 showed enhanced sensitivity to ABA. Physiological analyses showed that the overexpression of OsMLP423 may regulate the water loss efficiency and ABA-responsive gene expression of rice plants under drought and salt stresses, and it reduces membrane damage and the accumulation of reactive oxygen species. These results indicate that OsMLP423 is a positive regulator of drought and salinity tolerance in rice, governing the tolerance of rice to abiotic stresses through an ABA-dependent pathway. Therefore, this study provides a new insight into the physiological and molecular mechanisms of OsMLP423-mediated ABA signal transduction participating in drought and salt stresses.

Role of Abscisic Acid in Plant Stress

“…The discovery and characterization of ABREs have provided insight into the molecular mechanisms underlying ABA-mediated stress responses in plants. Studies in the promoter region of the Arabidopsis thaliana RD29A gene and rice OsRab16A gene contains contain one and three functional ABRE respectively, essential for the ABA-mediated induction of RD29A expression in response to dehydration stress and OsRab16A expression in response to salt stress [32,33]. Similar studies in wheat have shown that the promoter region of the wheat TaERF1 gene contains multiple ABREs that are involved in the ABA-mediated induction of TaERF1 expression in response to drought stress [34].…”

Overexpression of OsHAD3, a Member of HAD Superfamily, Decreases Drought Tolerance of Rice

“…Improving the antioxidant activity to reduce the over-production of ROS is the most useful way to enhance the stress tolerance in plants (Panda et al 2021 ), such as enhancing the activity of the POD and SOD (Gill and Tuteja 2010 ). Overexpression of OsMLP423 or OsSCL30 both reduced the damage caused by ROS through enhancing the activities of SOD and POD (Zhou et al 2022 ; Zhang et al 2022 ). Our result showed that overexpression of OsHAD3 could increase the over-accumulation of ROS but antisense-expression lines were opposite under drought stress condition, which could be further confirmed by the staining results of DAB and NBT and transcription level of genes, OsRbohA and OsRbohE .…”

Drought-Induced Changes in Leaf Morphology and Anatomy: Overview, Implications and Perspectives

“…Photosynthetic activity ceased by the extreme rolling of the leaves which is considered to not play a positive role in the other beneficial process in the plant. Therefore, the rolling approach of the leaves is the most critical process for the perfect functioning of the plants [72]. Bulliform cells are an example of a vital strategy to water conservation and photosynthesis enhancement.…”