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Cold stress response in Arabidopsis thaliana is mediated by GNOM ARF ‐ GEF
Author(s) -
Ashraf Mohammad A.,
Rahman Abidur
Publication year - 2019
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.14137
Subject(s) - arabidopsis , biology , mutant , microbiology and biotechnology , arabidopsis thaliana , transport protein , subcellular localization , mutation , genetics , gene , cytoplasm
Summary Endosomal trafficking plays an important role in regulating plant growth and development both at optimal and stressed conditions. Cold stress response in Arabidopsis root is directly linked to inhibition of the endosomal trafficking of auxin efflux carriers. However, the cellular components that link cold stress and the endosomal trafficking remain elusive. By screening available endosomal trafficking mutants against root growth recovery response under cold stress, we identified GNOM , a SEC 7 containing ARF ‐ GEF , as a major modulator of cold response. Contrasting response of partial loss of function mutant gnom B4049/emb30‐1 and the engineered Brefeldin A ( BFA )‐resistant GNOM line, both of which contain mutations within SEC 7 domain, to cold stress at the whole‐plant level highlights the importance of this domain in modulating the cold response pathway of plants. Cold stress selectively and transiently inhibits GNOM expression. The engineered point mutation at 696 amino acid position (Methionine to Leucine) that makes GNOM resistant to BFA in fact results in overexpression of GNOM both at transcriptional and translational levels, and also alters its subcellular localization. Overexpression and altered cellular localization of GNOM were found to be directly linked to conferring striking cold‐resistant phenotype in Arabidopsis. Collectively, these results provide a mechanistic link between GNOM , BFA ‐sensitive GNOM ‐regulated trafficking and cold stress.