Location: Sugarbeet and Potato ResearchTitle: Effects of heat stress on the endogenous contents of hormones and related gene expression in developing axillary tubes of potato
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/15/2015
Publication Date: 4/21/2016
Citation: Suttle, J.C., Olson, L.L., Lulai, E.C. 2016. Effects of heat stress on the endogenous contents of hormones and related gene expression in developing axillary tubes of potato [abstract]. American Journal of Potato Research. 93(2):143.
Technical Abstract: Potatoes are a cool season crop and optimum tuber initiation, development, yield, and quality require growing temperatures between 15 -20°C. At temperatures above 30°C, tuber initiation is delayed or prevented and developing tubers exhibit decreased starch content, increased malformation, chain-tuber formation, and heat sprouts. The latter three responses are the result of the loss of tuber (apical bud) dormancy. The effects of high (35°C) temperature, on the contents of endogenous hormones previously implicated in dormancy control and expression of their respective metabolic genes were determined in tuber axillary bud explants. Axillary tubers developed within 10 days on single-node explants excised from short-day induced plants. Following excision of the subtending leaf, developing axillary tubers were transferred to either 20° or 35°C and were harvested for analysis thereafter. Following transfer to 35°C, visible tuber apical bud sprout growth was initiated within 4-7 days. Between 24-48h following leaf excision, a dramatic decline in tuber ABA content was observed at both temperatures. Thereafter, ABA content in tubers exposed to 20°C began to increase, eventually exceeding those at leaf excision. In tubers exposed to 35°C, the ABA content continued to decline for the duration of the experiment. High-temperature induced decline in ABA content was accompanied by decreased expression of key ABA biosynthetic genes and increased expression of the principal ABA catabolic gene. The effects of high temperatures on the endogenous contents of cytokinins and gibberellins and their related metabolic genes are being determined and will be discussed.