Ethylene (ET) is a gaseous plant hormone that regulates many aspects of the plant life cycle, including biotic and abiotic stress responses. However, the role of ET in cold tolerance varies in different plant species.    

Grapevine (Vitis vinifera L.), a widely cultivated fruit crop, is negatively affected by the low temperature. To address this problem, researchers widely investigated the genetic mechanisms of cold acclimation in grapevine. However, the role of ET in the cold tolerance of grapevine remains unclear.    

Supervised by Professor LI Shaohua and associate professor XIN Haiping, SUN Xiaoming from Wuhan Botanical Garden investigated the relationship between cold stress and ET biosynthesis and the function of VaERF057 (an ET signaling downstream gene) by ectopic expression in Arabidopsis.  

Study demonstrated that cold stress increased ET production in grapevine. The application of exogenous1-aminocyclopropane-1-carboxylate (ACC) and the ET biosynthesis inhibitor aminoethoxyvinylglycine (AVG) respectively enhanced and reduced the cold tolerance of grapevine.    

The effects of cold stress on the expression of VaERF057 were totally inhibited when the plants were subjected with AVG under cold condition, which suggested that the response of VaERF057 possibly relies on the increased ET release during cold stress.    

The function of VaERF057 was analyzed in transgenic Arabidopsis to further investigate the possible role of VaERF057 in abiotic stress responses. The overexpression of VaERF057also enhanced the cold tolerance of Arabidopsis. Transcriptome sequencing results showed that 32 stress-related genes were upregulated in VaERF057-overexpressing transgenic line. Thus, VaERF057 may directly regulate the expression of its target stress-responsive genes by interacting with a GCC-boxor a dehydration-responsive element.    

This work confirmed that ET positively regulates cold tolerance in grapevine by modulating the expression of VaERF057.   

Results entitled “Ethylene positively regulates cold tolerance in grapevine by modulating the expression of ETHYLENE RESPONSE FACTOR 057”were published online on Scientific Reports.    

It was supported by the National Natural Science Foundation of China, National Key Technology R&D Program of the Ministry of Science and Technology during the Twelfth Five-year Plan Period and Youth Innovation Promotion Association of CAS. 

Low temperature increased ET production in grapevine (Image by SUN Xiaoming)