Location: Sustainable Perennial Crops LaboratoryTitle: Exogenous abscisic acid significantly affects proteome in tea plant (Camellia sinensis) exposed to drought stress Author
Submitted to: Horticulture Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/30/2014
Publication Date: 6/25/2014
Citation: Zhou, L., Xu, H., Mischke, B.S., Meinhardt, L.W., Zhang, D., Fang, W. 2014. Exogenous abscisic acid significantly affects proteome in tea plant (Camellia sinensis) exposed to drought stress. Horticulture Research. doi:10.1038/hortres.2014.29. Interpretive Summary: Tea is an important economic crop, and drought is one of the most important problems affecting yield and quality. Plant stress hormones are important regulators of how plants deal with drought. In this study the effects of drought and the addition of plant stress hormones were evaluated on the protein expression in tea leaves. These treatments modified the levels and types of proteins found in the leaves of tea plants and further suggest a role for plant stress hormones in how these plants tolerate drought. This information will be used by plant breeders and germplasm curators and will ultimately be used to improve tea varieties for the consumers.
Technical Abstract: Tea [Camellia sinensis (L.) O. Kuntze] is an important economic crop, and drought is the most important abiotic stress affecting yield and quality. Abscisic acid (ABA) is an important phytohormone responsible for activating drought resistance. Increased understanding of ABA effects on tea plant under drought stress is essential to develop drought-tolerant tea genotypes, along with crop management practices that can mitigate drought stress. The objective of the present investigation is evaluation of effects of exogenous ABA on the leaf proteome in tea plant exposed to drought stress. Leaf protein patterns of tea plants under simulated drought stress (PEG-treated) and exogenous ABA treatment were analyzed in a time-course experiment using two-dimensional electrophoresis (2-DE), followed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). Among the 72 protein spots identified by MALDI-TOF MS, 16 proteins were down-regulated and two were up-regulated by exogenous ABA. The up-regulated proteins have roles in glycolysis and photosystem II stabilization. Twenty-one protein spots were responsive to drought stress and most participate in carbohydrate and nitrogen metabolism, control of reactive oxygen species (ROS), defense, signaling, or nucleic acid metabolism. The combined treatments of exogenous ABA and drought showed up-regulation of 10 protein spots at 12 h and up-regulation of 11 proteins at 72 h after initiation of drought stress. The results support the importance of the role that ABA plays in the tea plant during drought stress, by improving protein transport, carbon metabolism and expression of resistance proteins.