Abstract
Jasmonic acid (JA) plays an important role in regulating leaf senescence. However, the molecular mechanisms of leaf senescence in apple (Malus domestica) remain elusive. In this study, we found that MdZAT10, a C2H2-type zinc finger transcription factor (TF) in apple, markedly accelerates leaf senescence and increases the expression of senescence-related genes. To explore how MdZAT10 promotes leaf senescence, we carried out liquid chromatography/mass spectrometry screening. We found that MdABI5 physically interacts with MdZAT10. MdABI5, an important positive regulator of leaf senescence, significantly accelerated leaf senescence in apple. MdZAT10 was found to enhance the transcriptional activity of MdABI5 for MdNYC1 and MdNYE1, thus accelerating leaf senescence. In addition, we found that MdZAT10 expression was induced by methyl jasmonate (MeJA), which accelerated JA-induced leaf senescence. We also found that the JA-responsive protein MdBT2 directly interacts with MdZAT10 and reduces its protein stability through ubiquitination and degradation, thereby delaying MdZAT10-mediated leaf senescence. Taken together, our results provide new insight into the mechanisms by which MdZAT10 positively regulates JA-induced leaf senescence in apple.
Highlights
Plant leaf senescence, the last stage of leaf development, is accompanied by a series of physiological and biochemical changes, including the degradation of intracellular organelles and hydrolysis of macromolecules for the relocation of nutrients and energy into newly developing tissues or storage organs[1]
All proteins contained two conserved zinc finger domains and an ERF-associated amphiphilic repression (EAR) motif, and MdZAT10 was highly homologous to PbZAT10 from Pyrus bretschneideri (Supplementary Fig. S1)
We found that MdZAT10 overexpression increased the expression of MdNYC1 and MdNYE1 in apple leaves (Fig. 1g, h)
Summary
The last stage of leaf development, is accompanied by a series of physiological and biochemical changes, including the degradation of intracellular organelles and hydrolysis of macromolecules for the relocation of nutrients and energy into newly developing tissues or storage organs[1]. Plant hormones are known to affect the timing of leaf senescence. Hormones such as abscisic acid (ABA), jasmonic acid, ethylene (ET), and salicylic acid (SA) accelerate the leaf senescence process, whereas auxin, cytokinins (CKs), and gibberellic acid (GA) delay leaf senescence[9]. JA is a lipid-derived phytohormone that is ubiquitous in the plant kingdom and plays essential roles in the regulation of multiple physiological processes in plants, including root growth, leaf senescence, and the response to wounding and pathogens[10,11,12,13].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
