The Effect of TRANSPARENT TESTA2 on Seed Fatty Acid Biosynthesis and Tolerance to Environmental Stresses during Young Seedling Establishment in Arabidopsis
The Effect of TRANSPARENT TESTA2 on Seed Fatty Acid Biosynthesis and Tolerance to Environmental Stresses during Young Seedling Establishment in Arabidopsis
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DOI：
10.1104/pp.112.202945
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发表时间：
2012-10-01
期刊：
影响因子：
7.4
通讯作者：
Jiang, Lixi
中科院分区：
文献类型：
--
作者：
Chen, Mingxun;Wang, Zhong;Jiang, Lixi
在植物中，脂肪酸（FA）和FA衍生的复合脂质是种子中主要的碳和能量储备。它们是细胞膜和细胞信号或激素分子的基本组成部分。尽管透明种皮2（TT2）在调节种皮中原花色素生物合成中的功能被充分研究，但很少注意其在影响种子FA积累和对环境胁迫的耐受性中的作用。我们证明，tt2突变显着增加种子FA含量，降低种子重量，并改变FA组成。在tt2种子中FA含量的增加是由于相对减少的种皮比例，以及更有效的FA合成在tt2胚。基因芯片分析表明，tt2突变上调了一组关键的FA生物合成和胚胎发育的基因。这种突变也改变了对压力做出反应的基因表达。微阵列分析发现，tt2种子中FA积累的增加伴随着胚胎发育转录因子FUSCA 3和催化FA链延伸的脂肪酸延伸酶1的显著上调。此外，种子成熟过程中较低的种子蛋白质积累也有助于增加种子FA积累的tt2突变体。本研究进一步了解TT2基因在种子萌发和幼苗建立过程中的FA积累和非生物胁迫。
In plants, fatty acids (FAs) and FA-derived complex lipids are major carbon and energy reserves in seeds. They are essential components of cellular membranes and cellular signal or hormone molecules. Although TRANSPARENT TESTA2 (TT2) is well studied for its function in regulating proanthocyanidin biosynthesis in the seed coat, little attention has been given to its role in affecting seed FA accumulation and tolerance to environmental stresses. We demonstrate that the tt2 mutation remarkably increased the seed FA content, decreased seed weight, and altered the FA composition. The increase in FA content in the tt2 seeds was due to the relative decrease of seed coat proportion as well as the more efficient FA synthesis in the tt2 embryo. Microarray analysis revealed that tt2 mutation up-regulated a group of genes critical to FA biosynthesis and embryonic development. The mutation also altered the gene expressions that respond to stress. The microarray analysis discovered that the increase in FA accumulation of the tt2 seeds were accompanied by the significant up-regulation of FUSCA3, a transcriptional factor for embryonic development and FATTY ACID ELONGASE1, which catalyzes the elongation of FA chains. Moreover, lower seed protein accumulation during seed maturation also contributed to the increased seed FA accumulation in tt2 mutants. This study advances the understanding of the TT2 gene in seed FA accumulation and abiotic stresses during seed germination and seedling establishment.