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A homolog of ETHYLENE OVERPRODUCER , O s ETOL 1, differentially modulates drought and submergence tolerance in rice
Author(s) -
Du Hao,
Wu Nai,
Cui Fei,
You Lei,
Li Xianghua,
Xiong Lizhong
Publication year - 2014
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.12508
Subject(s) - mutant , oryza sativa , biology , ethylene , panicle , wild type , biochemistry , abiotic stress , biosynthesis , gene , arabidopsis , mutagenesis , drought tolerance , microbiology and biotechnology , botany , catalysis
Summary Submergence and drought are major limiting factors for crop production. However, very limited studies have been reported on the distinct or overlapping mechanisms of plants in response to the two water extremes. Here we report an ETHYLENE OVERPRODUCER 1 ‐like gene ( O s ETOL 1) that modulates differentially drought and submergence tolerance in rice ( O ryza sativa L.). Two allelic mutants of O s ETOL 1 showed increased resistance to drought stress at the panicle development stage. Interestingly, the mutants exhibited a significantly slower growth rate under submergence stress at both the seedling and panicle development stages. O ver‐expression ( OE ) of O s ETOL 1 in rice resulted in reverse phenotypes when compared with the mutants. The O s ETOL 1 transcript was differentially responsive to abiotic stresses. O s ETOL 1 was found to interact with O s ACS 2, a homolog of 1‐amino‐cyclopropane‐1‐carboxylate ( ACC ) synthase ( ACS ), which acts as a rate‐limiting enzyme for ethylene biosynthesis. In the osacs2 mutant and O s ETOL 1 ‐ OE plants, ACC and ethylene content were decreased significantly, and exogenous ACC restored the phenotype of osetol1 and O s ETOL 1 ‐ OE to wild‐type under submergence stress, implying a negative role for O s ETOL 1 in ethylene biosynthesis. The expression of several genes related to carbohydrate catabolism and fermentation showed significant changes in the osetol1 and O s ETOL 1 ‐ OE plants, implying that O s ETOL 1 may affect energy metabolism. These results together suggest that O s ETOL 1 plays distinct roles in drought and submergence tolerance by modulating ethylene production and energy metabolism. Findings from the expression and functional comparison of three ethylene overproducer ( ETOL ) family members in rice further supported the specific role of O s ETOL 1 in the responses to the two water stresses.