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Isolation and functional characterization of the Arabidopsis salt‐tolerance 32 ( AtSAT32 ) gene associated with salt tolerance and ABA signaling
Author(s) -
Park MinYoung,
Chung MoonSoo,
Koh HeeSeok,
Lee Dong J.,
Ahn SungJu,
Kim Cheol S.
Publication year - 2009
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/j.1399-3054.2008.01202.x
Subject(s) - arabidopsis , silique , biology , complementary dna , mutant , gene , arabidopsis thaliana , abscisic acid , microbiology and biotechnology , botany , genetics
Recently, we have isolated salt‐tolerance genes (SATs) on the basis of the overexpression screening of yeast with a maize cDNA library from kernels. One of the selected genes [ salt‐tolerance 32 ( SAT32 )] appears to be a key determinant for salt stress tolerance in yeast cells. Maize SAT32 cDNA encodes for a 49‐kDa protein, which is 41% identity with the Arabidopsis salt‐tolerance 32 ( AtSAT32 ) unknown gene. Arabidopsis Transfer‐DNA (T‐DNA) knockout AtSAT32 ( atsat32 ) altered root elongation, including reduced silique length and reduced seed number. In an effort to further assess salinity tolerance in Arabidopsis , we have functionally characterized the AtSAT32 gene and determined that salinity and the plant hormone ABA induced the expression of AtSAT32 . The atsat32 mutant was more sensitive to salinity than the wild‐type plant. On the contrary, Arabidopsis overexpressing AtSAT32 (35S:: AtSAT32 ) showed enhanced salt tolerance and increased activity of vacuolar H + ‐pyrophosphatase (V‐PPase, EC 3.6.1.1) under high‐salt conditions. Consistent with these observations, 35S:: AtSAT32 plants exhibited increased expression of salt‐responsive and ABA‐responsive genes, including the Rd29A , Erd15 , Rd29B , Rd22 and RAB18 genes. Therefore, our results indicate that AtSAT32 is involved in both salinity tolerance and ABA signaling as a positive regulator in Arabidopsis .