Mild Water Deficit In The Field Down Regulated Drought Responsive Genes In Peanut Leaf Tissues

Drought is a major abiotic stress limiting production of cultivated peanut (Arachis hypogaea L.). Exposure of plants to mild water deficit at early developmental stage has potential to maintain pod yield equal to fully irrigated plants in some cropping systems. The molecular mechanism regulating peanut response to mild water deficit at field condition is unknown. To explore possible gene responses under mild water deficit, 11 peanut putative drought responsive genes were examined at 34 and 92 days after planting in the leaf tissues of Florida-07 and Tifguard cultivars treated with either mild water deficit or full irrigation. The results showed that the mild water deficit suppressed the expressions of three transcriptional factor genes, AhMYB (P = 0.028), AhNAC (P = 0.047) and AhZFP (P = 0.038), indicating that plant might use different gene expression profile to cope with mild water deficit and severe drought conditions. Three genes, AhAREB1, AhMYB, and AhZFP expressed differently between the two cultivars indicating the different genetic background could impact the gene expression levels. Expressions of eight of the 11 genes were impacted by crop developmental stages. Though none of the 11 genes were upregulated by the mild water deficit in the peanut field, the results in this study approved the sensitivities of RT-qPCR in detecting gene expression at different field conditions and provided a quick glimpse and incentive for further investigation of molecular mechanisms of crops in response to mild and severe water deficit in the field conditions. (C) 2018 Friends Science Publishers