TRANSPARENT TESTA2 regulates embryonic fatty acid biosynthesis by targeting FUSCA3 during the early developmental stage of Arabidopsis seeds
TRANSPARENT TESTA2 regulates embryonic fatty acid biosynthesis by targeting FUSCA3 during the early developmental stage of Arabidopsis seeds
复制标题
TRANSPARENT TESTA2 在拟南芥种子早期发育阶段通过靶向 FUSCA3 调节胚胎脂肪酸生物合成
DOI：
10.1111/tpj.12426
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发表时间：
2014
期刊：
影响因子：
7.2
通讯作者：
Jiang LX
中科院分区：
文献类型：
--
作者：
Wang Z;Chen MX;Chen TL;Xuan LJ;Li ZL;Du X;Zhou LH;Zhang GP;Jiang LX
透明TESTA2(TT2)调控拟南芥种皮中原花青素的生物合成。我们最近发现，TT2还参与了抑制种子胚胎中脂肪酸(FA)的生物合成。然而，TT2抑制种子FA积累的机制尚不清楚。在本研究中，我们发现TT2在发育早期的胚胎中表达。TT2直接与FUSCA3(FUS3)的调控区结合，在FA生物合成途径中调节多种基因的表达。这些基因包括BCCP2、CaC2、MOD1和KASII，它们编码参与FA链形成的初始步骤的蛋白质；FAD2和FAD3，它们负责FA的去饱和化；FAE1，它催化FA超长链的延长。TT2功能的丧失导致GLABRA2的表达减少，但不会导致附着在种皮上的粘液显著减少，后者与FA竞争光合作用。TT2在母体种皮和胚胎组织中都有表达，但原花青素只在野生型种皮中存在，在胚胎组织中不存在。种皮中原花青素含量与胚中FAs含量呈负相关。
TRANSPARENT TESTA2 (TT2) regulates the biosynthesis of proanthocyanidins in the seed coat of Arabidopsis. We recently found that TT2 also participates in inhibition of fatty acid (FA) biosynthesis in the seed embryo. However, the mechanism by which TT2 suppresses the accumulation of seed FA remains unclear. In this study, we show thatTT2is expressed in embryos at an early developmental stage. TT2 is directly bound to the regulatory region ofFUSCA3(FUS3), and mediates the expression of numerous genes in the FA biosynthesis pathway. These genes includeBCCP2,CAC2,MOD1andKASII, which encode proteins involved in the initial steps of FA chain formation,FAD2andFAD3, which are responsible for FA desaturation, andFAE1, which catalyzes very‐long‐chain FA elongation. Loss of function ofTT2results in reduced expression ofGLABRA2but does not cause a significant reduction in the mucilage attached to the seed coats, which competes with FA for photosynthates.TT2is expressed in both maternal seed coats and embryonic tissues, but proanthocyanidins are only found in wild‐type seed coats and not in embryonic tissues. The amount of proanthocyanidins in the seed coat is negatively correlated with the amount of FAs in the embryo.