Mutation of OsMYB60 reduces rice resilience to drought stress by attenuating cuticular wax biosynthesis

Abstract

SUMMARY The cuticular wax layer on leaf surfaces limits non‐stomatal water loss to the atmosphere and protects against pathogen invasion. Although many genes associated with wax biosynthesis and wax transport in plants have been identified, their regulatory mechanisms remain largely unknown. Here, we show that the MYB transcription factor OsMYB60 positively regulates cuticular wax biosynthesis and this helps rice (Oryza sativa) plants tolerate drought stress. Compared with the wild type (japonica cultivar ‘Dongjin’), osmyb60 null mutants (osmyb60‐1 and osmyb60‐2) exhibited increased drought sensitivity, with more chlorophyll leaching and higher rates of water loss. Quantitative reverse‐transcription PCR showed that the loss of function of OsMYB60 led to downregulation of wax biosynthesis genes, leading to reduced amounts of total wax components on leaf surfaces under normal conditions. Yeast one‐hybrid, luciferase transient transcriptional activity, and chromatin immunoprecipitation assays revealed that OsMYB60 directly binds to the promoter of OsCER1 (a key gene involved in very‐long‐chain alkane biosynthesis) and upregulates its expression. Taken together, these results demonstrate that OsMYB60 enhances rice resilience to drought stress by promoting cuticular wax biosynthesis on leaf surfaces.

Genome-Wide Identification Analysis of the R2R3-MYB Transcription Factor Family in Cymbidium sinense for Insights into Drought Stress Responses

“…It has been widely investigated in Arabidopsis , rice, and wheat that R2R3-MYB genes are involved in regulating responses to drought stress [ 5 , 11 , 12 , 13 , 33 ]. Among the other species, GaMYB85 of Gossypium aridum , homolog with AtMYB85 from S8, reportedly play an important role in the drought tolerance of plants [ 34 ].…”

“…Similarly, OsMYB4 causes high levels of several amino acids involved in stress adaptation. OsMYB60 promotes cuticular wax biosynthesis on leaf surfaces to enhance plant resilience to drought stress [ 11 , 12 , 13 ]. R2R3-MYB TF in wheat ( Triticum aestivum ) TaPIMP1 is involved in drought response by binding to the MYB-binding site and activates the expression of the genes with the Myb cis -element.…”

Small Papillae Regulated by SPD25 are Critical for Balancing Photosynthetic CO2 Assimilation and Water Loss in Rice

“…The leaf surface plays a key role in protection against multiple stress factors such as water loss, overheating and insect or pathogen attack (Jian et al 2022 ; Johnson et al 2002 ). The cuticle-Si double layer formed by the leaf epidermis and cuticle can reduce transpiration loss in leaves (Hattori et al 2005 ; Ma and Yamaji 2006 ; Wang et al 2021 ).…”

Genome-wide analysis of R2R3-MYB genes in cultivated peanut (Arachis hypogaea L.): Gene duplications, functional conservation, and diversification

“…MsMYB741 is involved in alfalfa resistance to aluminum stress by regulating flavonoid biosynthesis (Su et al 2022). OsMYB60 positively regulates cuticular wax biosynthesis and this helps rice (Oryza sativa) plants tolerate drought stress (Jian et al, 2022).…”

“…2022 ). OsMYB60 positively regulates cuticular wax biosynthesis and this helps rice ( Oryza sativa ) plants tolerate drought stress ( Jian et al., 2022 ).…”