The research group of Greenhouse Crop Biology in the Institute of Vegetable Sciences, Zhejiang University recently published an article entitled “A Plant Phytosulfokine Peptide Initiates Auxin-Dependent Immunity through Cytosolic Ca2+ Signaling in Tomato” in The Plant Cell. Their discovery provides new insights into small peptide-mediated control of plant immunity.
Peptide signalling has critical roles in regulating plant physiology. Phytosulfokine (PSK) is a secreted disulfated pentapeptide (YIYTQ) that has ubiquitous roles in plant growth, development and immunity. However, the signaling mechanisms and pathways that PSK activates are unknown. The research group of “Greenhouse Crop Biology” found that biosynthesis, modification, and perception of PSK all are crucial for PSK-mediated plant immunity against B. cinerea. Upon PSK perception by the tomato PSK receptor PSKR1, cytosolic Ca2+ accumulates as a consequence of PSKR1-mediated calcium channel activation. They further identified calmodulin as the calcium binding sensor that interacts with auxin biosynthesis enzymes known as YUCs, leading to auxin biosynthesis and initiating the auxin-mediated plant immunity signaling pathway against B. cinerea.
Botrytis cinerea is a very broad host, and the gray mold caused by it is an important disease of crops such as tomato, grape, strawberry and pepper. At present, there is still a lack of resistant varieties for the disease in production, and rely on the use of chemical bactericides to control. The study found that the PSK peptide hormones play an active role in plant defense against gray mold. PSK peptide hormones can also regulate the growth and development of plants. The further in-depth study might provide bases for regulating crop production in terms of gray mold controls.
Because of the interesting nature of the work, this paper will be highlighted with an “In Brief” article in The Plant Cell.
Except for the work from Prof. Jingquan Yu’s lab, Prof. Xinzhong Cai from Institute of Biotechnology, Zhejiang University and Prof. Christin Foyer from University of Leeds also contributed significantly to this work. The Ph. D students, Miss Huan Zhang and Mr Zhangjian Hu are the first co-authors. Prof. Kai Shi is the corresponding author. This research was supported by the National Natural Science Foundation of China and the National Basic Research Program of China.
Full article linkage：http://www.plantcell.org/content/early/2018/03/06/tpc.17.00537