Recently, the Grape Germplasm Resources and Genetic Breeding Team of the College of Horticulture, Northwest A&F University, published an online publication titled”Overexpression of two CDPKs from wild Chinese grapevine enhances powdery mildew resistance in Vitis” in”New Phytologist”. vinifera and Arabidopsis” research paper. Hu Yang, a 2017 doctoral student in the College of Horticulture, is the first author of the paper, and Professor Wen Yingqiang is the corresponding author.
Powdery mildew seriously harms grape production and causes huge economic losses every year. The widely cultivated Eurasian grapes are of good quality, but they lack effective genetic resistance to powdery mildew. It has been identified that some Chinese wild grapes (strains) are highly resistant to powdery mildew and are important germplasm resources for molecular breeding of disease resistance of grapes. Ca2+ is an important second messenger molecule in plant cells. When plant cells are stimulated by the invasion of pathogens, the calcium ion concentration in the cytoplasm will periodically oscillate (ie, calcium signals). Calcium-dependent protein kinases (CDPKs) bind Ca2+ through their carboxy-terminal calcineurin domain (EF-hand) and change their own conformation, exposing the kinase active site; then, CDPKs bind to substrate proteins or promote their phosphorylation, The calcium signal is converted into a phosphorylation event, and then the stress signal is transmitted to downstream transcription factors, protein kinases or terminal metabolic enzymes and other substrate proteins. Therefore, calcium-dependent protein kinase may play a key regulatory function in the interaction between grape and powdery mildew. This study identified two class I CDPK genes (VpCDPK9/13) that were up-regulated in response to powdery mildew induced by the white river-35-1 of the East China grape strain, which was highly resistant to powdery mildew; VpCDPK9/13-YFP was obtained through genetic transformation. Overexpressing transgenic grape lines and VpCDPK9-YFP overexpressing transgenic Arabidopsis lines. The results of disease resistance identification showed that the powdery mildew resistance of the genetically modified materials was significantly enhanced compared to the wild-type, and it was mainly attributed to the allergic death of host cells, cell wall deposition and hydrogen peroxide accumulation induced by powdery mildew, and was dependent on ethylene and water. Salicylic acid signal; biochemical analysis shows that VpCDPK9/13 can interact with VpMAPK3, VpMAPK6, VpACS1 and VpACS2 to regulate the phosphorylation and protein accumulation of the latter to participate in the regulation of ethylene biosynthesis; the results of field hormone determination of grape leaves show that:The accumulation level of powdery mildew resistant wild grape lines is higher, while the accumulation level is very low in powdery mildew-susceptible wild grape lines. This phenomenon does not exist in European grapes, indicating that ethylene may play an important role in the resistance of Chinese wild grapes to powdery mildew. This research provides a theoretical basis for the use of Chinese wild grape disease resistance gene resources to cultivate grape disease resistance molecular breeding.
The research was completed in cooperation between the College of Horticulture and the University of Maryland, and was funded by the National Key Research and Development Program, the National Natural Science Foundation of China, and the US NSF program.
link to the original text:https://nph.onlinelibrary.wiley.com/doi/abs/10.1111/nph.17285