Two B3 domain transcriptional repressors prevent sugar-inducible expression of seed maturation genes in Arabidopsis seedlings
Two B3 domain transcriptional repressors prevent sugar-inducible expression of seed maturation genes in Arabidopsis seedlings
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DOI：
10.1073/pnas.0607940104
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发表时间：
2007-02-13
影响因子：
11.1
通讯作者：
Nakamura, Kenzo
中科院分区：
文献类型：
--
作者：
Tsukagoshi, Hironaka;Morikami, Atsushi;Nakamura, Kenzo
在植物种子的发育过程中，胚胎输入营养物质并储存大量储备。种子储备迅速退化，并在发芽后被动员起来支持幼苗发育。拟南芥糖诱导基因2（HSI 2）的高效表达是一种抑制糖诱导报告基因转录的B3 DNA结合域蛋白。尽管HSI 2或HSI 2样1（HSL 1）的破坏不影响生长，但具有HSI 2和HSL 1两者的破坏的种子（KK突变体）发育出在吸胀后7-9天停止生长的败育幼苗。KK幼苗发育出膨大的下胚轴，在含有蔗糖或其他代谢糖的培养基上积累种子贮藏蛋白和油，并且从KK幼苗发育出的愈伤组织也积累种子贮藏储备。种子成熟基因的表达，其中包括叶子叶型主调节因子，在KK幼苗依赖于蔗糖的浓度，表明糖控制种子成熟基因的表达。我们的研究结果表明，HSI 2和HSL 1抑制种子成熟程序在幼苗中的糖诱导表达，并在调节从种子成熟到幼苗生长的过渡中发挥重要作用。
During development of plant seeds, embryos import nutrients and store massive amounts of reserves. Seed reserves are rapidly degraded and mobilized to support seedling development after germination. HIGH-LEVEL EXPRESSION OF SUGAR-INDUCIBLE GENE 2 (HSI2) of Arabidopsis thaliana is a B3 DNA-binding domain protein that represses the transcription of sugar-inducible reporter gene. Although disruption of HSI2 or HSI2-Like 1 (HSL1) did not affect growth, seeds with disruption of both HSI2 and HSL1 (KK mutant) developed abortive seedlings that stopped growing 7-9 days after imbibition. KK seedlings developed swollen hypocotyls that accumulated seed storage proteins and oil on medium containing sucrose or other metabolizable sugars, and calluses developed from KK seedlings also accumulated seed storage reserves. The expression of seed maturation genes, which include LEAFY COTYLEDON-type master regulators, in KK seedlings depended on the concentration of sucrose, suggesting that sugar controls the expression of seed maturation genes. Our results suggest that HSI2 and HSL1 repress the sugar-inducible expression of the seed maturation program in seedlings and play an essential role in regulating the transition from seed maturation to seedling growth.