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WRI 1‐1, ABI 5, NF ‐ YA 3 and NF ‐ YC 2 increase oil biosynthesis in coordination with hormonal signaling during fruit development in oil palm
Author(s) -
Yeap WanChin,
Lee FongChin,
Shabari Shan Dilip Kumar,
Musa Hamidah,
Appleton David Ross,
Kulaveerasingam Harikrishna
Publication year - 2017
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.13549
Subject(s) - wrky protein domain , biology , transcription factor , biosynthesis , repressor , gene , biochemistry , signal transduction , promoter , microbiology and biotechnology , gene expression , transcriptome
Summary The oil biosynthesis pathway must be tightly controlled to maximize oil yield. Oil palm accumulates exceptionally high oil content in its mesocarp, suggesting the existence of a unique fruit‐specific fatty acid metabolism transcriptional network. We report the complex fruit‐specific network of transcription factors responsible for modulation of oil biosynthesis genes in oil palm mesocarp. Transcriptional activation of Eg WRI 1‐1 encoding a key master regulator that activates expression of oil biosynthesis genes, is activated by three ABA ‐responsive transcription factors, Eg NF ‐ YA 3, Eg NF ‐ YC 2 and Eg ABI 5. Overexpression of Eg WRI 1‐1 and its activators in Arabidopsis accelerated flowering, increased seed size and oil content, and altered expression levels of oil biosynthesis genes. Protein–protein interaction experiments demonstrated that Eg NF ‐ YA 3 interacts directly with Eg WRI 1‐1, forming a transcription complex with Eg NF ‐ YC 2 and Eg ABI 5 to modulate transcription of oil biosynthesis pathway genes. Furthermore, Eg ABI 5 acts downstream of Eg WRKY 40, a repressor that interacts with Eg WRKY 2 to inhibit the transcription of oil biosynthesis genes. We showed that expression of these activators and repressors in oil biosynthesis can be induced by phytohormones coordinating fruit development in oil palm. We propose a model highlighting a hormone signaling network coordinating fruit development and fatty acid biosynthesis.