Open AccessSalt and oxidative stresses uniquely regulate tomato cytokinin levels and transcriptomic response
Author(s) -
Keshishian Erika A.,
Hallmark H. Tucker,
Ramaraj Thiruvarangan,
Plačková Lenka,
Sundararajan Anitha,
Schilkey Faye,
Novák Ondřej,
Rashotte Aaron M.
Publication year - 2018
Publication title -
plant direct
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.211
H-Index - 11
ISSN - 2475-4455
DOI - 10.1002/pld3.71
Subject(s) - cytokinin , transcriptome , oxidative stress , biology , plant physiology , microbiology and biotechnology , plant hormone , biochemistry , botany , gene , gene expression , auxin
Abstract Cytokinins are well‐known to be involved in processes responsible for plant growth and development. More recently, these hormones have begun to be associated with stress responses as well. However, it is unclear how changes in cytokinin biosynthesis, signaling, or transport relate to stress effects. This study examines in parallel how two different stresses, salt, and oxidative stress, affect changes in both cytokinin levels and whole plant transcriptome response. Solanum lycopersicum seedlings were given a short‐term (6 hr) exposure to either salt (150 mM NaCl) or oxidative (20 mM H 2 O 2 ) stress and then examined to determine both changes in cytokinin levels and transcriptome. LC ‐ MS / MS was used to determine the levels of 22 different types of cytokinins in tomato plants including precursors, active, transported, and conjugated forms. When examining cytokinin levels we found that salt treatment caused an increase in both active and inactive cytokinin levels and oxidative stress caused a decrease in these levels. RNA ‐sequencing analyses of these same stress‐treated tissues revealed 6,643 significantly differentially expressed genes ( DEG s). Although many DEG s are similar between the two stresses, approximately one‐third of the DEG s in each treatment were unique to that stress. Several cytokinin‐related genes were among the DEG s. Examination of photosystem II efficiency revealed that cytokinins affect physiological response to stress in tomato, further validating the changes in cytokinin levels seen in planta .