TESTA TRANSPARENT (TT) genes, in particular, some transcriptional factors such as TT2, TTG1 and TT8, are well known for their function in regulating the key steps on the flavonoid/proanthocyanidin biosynthesis pathway in Arabidopsis. However, recent studies in Prof. Lixi Jiang’s lab of College of Agriculture and Biotechnology, Zhejiang University reveals that TT genes also regulate the biosynthesis of embryonic fatty acids. Their first study reporting the effect of TT2 on seed fatty acid synthesis and tolerance to environmental stresses during young seedling establishment was published in Plant Physiology (Chen et al., 2012. Plant Physiology 160:1023-1036). Early this year, they discovered that TT2 regulates embryonic fatty acid biosynthesis by targeting FUSCA3 during early developmental stage of seeds (Wang et al., 2014. Plant Journal 77:757-769). More recently, they further characterized the maternal effect of TT8 and its role in inhibiting seed fatty acid accumulation and the interactions between TT8 and LEAFY COTYLEDON1, LEAFY COTYLEDON2, FUSCA3, the three most important regulators for seed development (Chen et al., 2014. Plant Physiology: doi: 10.1104/pp.114.235507). Since their first report discovering Seed Fatty Acid Reducers (Chen et al., 2012. Plant Cell and Environment 35:2155-2169 ), the scientists of the lab aroused interests of biologists and oilseed breeders at the negative elements in the process of seed fatty acid accumulation. Their researches implicate that the interference of the function of the above TT genes and SFAR orthologs in rapeseed would result in a probable elevation of oil content in seeds.
The work in Prof. Jiang’s lab was financed by the Natural Science Foundation of China and the Ministry of Education.