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Exogenous methyl jasmonate promotes salt stress‐induced growth inhibition and prioritizes defense response of Nitraria tangutorum Bobr.
Author(s) -
Gao Ziqi,
Gao Shuai,
Li Pengxuan,
Zhang Yan,
Ma Binjie,
Wang Yingchun
Publication year - 2021
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/ppl.13314
Subject(s) - methyl jasmonate , abscisic acid , jasmonic acid , jasmonate , gibberellin , biology , plant defense against herbivory , cytokinin , biochemistry , biosynthesis , microbiology and biotechnology , salicylic acid , botany , auxin , gene , arabidopsis , mutant
Jasmonates (JAs) play a key role in the regulation of growth and the defense response to environmental stresses. JAs inhibit plant growth and promote defense response. However, their roles in desert halophyte in the response to salt stress remain poorly understood. The effects of the combination of methyl jasmonate (MeJA) and NaCl treatment (the “MeN” condition) on the growth regulation and defense response of Nitraria tangutorum seedlings were investigated. Compared with NaCl treatment alone, exogenous MeJA aggravated the growth inhibition of seedlings by antagonizing to growth‐related hormones and suppressing the transcript levels of these hormones‐responsive genes, including gibberellin (GA)‐responsive NtPIF3 , NtGAST1 , NtGSAT4 , and cytokinin (CYT)‐responsive NtARR1 , NtARR11 , NtARR12 . Meanwhile, exogenous MeJA enhanced defense response and alleviated the stress damage by increasing antioxidase activity and antioxidant content, accumulating more osmolytes, maintaining lower Na + /K + ratios in shoots and higher Na + efflux rates in roots of plants. In addition, exogenous MeJA increased the contents of endogenous JA and ABA, and the transcript levels of genes involved in their biosynthesis and responsiveness, thereby further regulating the transcript levels of defense response genes. These findings suggest that exogenous MeJA increases salt stress‐induced growth inhibition and prioritizes the defensive responses (e.g. antioxidant defense, osmotic adjustment, and ion homeostasis) of N. tangutorum . These effects may be related to the amplification of jasmonic acid (JA) and abscisic acid (ABA) signals.