745 / 2019-05-15 08:24:56

Effect of long-term ABA treatment on chloroplast biogenesis and abiotic stress responses

long-term ABA treatment,leaf yellowing,dehydration stress response,leucine-rich repeat kinase,chloroplast biogenesis

全体主题 > Abiotic Stress

For plants having the sessile life style, water availability profoundly affects the growth and development. Indeed, plants contain mechanisms to respond to the dehydration conditions and the responses should be finely tuned to the exact conditions of the stress. In this process, ABA plays a crucial role in mediating dehydration stress responses. In addition to the abiotic stress responses, long-term ABA treatment caused leaf yellowing phenotype whereas the short term treatment increases chlorophyll levels. Dehydration and chloroplast biogenesis-related genes showed strong induction at 24 to 48 h after treatment and then declined to lower levels at later time points. Thus, the mode of ABA responses changes at 24 to 48 h after ABA treatment from the early response mode, the activation of gene expression, to the late response mode, the suppression of gene expression. We identified a leucine-rich repeat kinase that plays a crucial role in ABA-induced leaf yellowing. The kinase belongs to the well-known leucine-rich repeat kinase family and localized to the plasma membrane. A T-DNA insertion mutant showed the defect in ABA-induced leaf yellowing, less sensitive to ABA in germination and enhanced sensitivity to dehydration stress. I will discuss about the link between ABA-induced leaf yellowing and ABA-mediated abiotic stress responses.