Trehalose-6-phosphate synthase/phosphatase regulates cell shape and plant architecture in Arabidopsis
Trehalose-6-phosphate synthase/phosphatase regulates cell shape and plant architecture in Arabidopsis
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DOI：
10.1104/pp.107.107441
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发表时间：
2008-01-01
期刊：
影响因子：
7.4
通讯作者：
Raikhel, Natasha V.
中科院分区：
文献类型：
--
作者：
Chary, S. Narasimha;Hicks, Glenn R.;Raikhel, Natasha V.
液泡占据植物细胞的大部分体积;因此，液泡膜标记物δ-液泡膜内在蛋白-绿色荧光蛋白描绘细胞形状，例如，在表皮中。这允许快速鉴定突变体。利用这种策略，我们确定了细胞形状表型-1（csp-1）突变体在拟南芥。除了在铺面细胞的裂片的情况下，表型包括减少毛状体分支，改变叶锯齿和茎分支，气孔密度增加。这是由于AtTPS 6中编码保守氨基末端结构域（被认为催化海藻糖-6-磷酸合成）和羧基末端磷酸酶结构域的点突变，催化两步转化为海藻糖。AtTPS 6在酿酒酵母突变体tps 1（编码合成酶结构域）和tps 2（编码合成酶和磷酸酶结构域）中的表达表明AtTPS 6是活性海藻糖合成酶。AtTPS 6完全补充了csp-1中的缺陷。I类基因（AtTPS 1-AtTPS 4）的突变表明在调节淀粉储存，抗旱性和花序结构中的作用。II类基因（AtTPS 5-AtTPS 11）编码具有合成酶和磷酸酶活性的多功能酶。我们发现，II类AtTPS 6调节植物的结构，表皮铺面细胞的形状，和毛状体的分支。因此，除了在发展中的作用，我们证明了II类基因AtTPS 6是重要的控制细胞形态发生。
The vacuole occupies most of the volume of plant cells; thus, the tonoplast marker delta-tonoplast intrinsic protein- green fluorescent protein delineates cell shape, for example, in epidermis. This permits rapid identification of mutants. Using this strategy, we identified the cell shape phenotype-1 (csp-1) mutant in Arabidopsis thaliana. Beyond an absence of lobes in pavement cells, phenotypes included reduced trichome branching, altered leaf serration and stem branching, and increased stomatal density. This result from a point mutation in AtTPS6 encoding a conserved amino-terminal domain, thought to catalyze trehalose-6-phosphate synthesis and a carboxy-terminal phosphatase domain, is catalyzing a two-step conversion to trehalose. Expression of AtTPS6 in the Saccharomyces cerevisiae mutants tps1 (encoding a synthase domain) and tps2 (encoding synthase and phosphatase domains) indicates that AtTPS6 is an active trehalose synthase. AtTPS6 fully complemented defects in csp-1. Mutations in class I genes (AtTPS1-AtTPS4) indicate a role in regulating starch storage, resistance to drought, and inflorescence architecture. Class II genes (AtTPS5-AtTPS11) encode multifunctional enzymes having synthase and phosphatase activity. We show that class II AtTPS6 regulates plant architecture, shape of epidermal pavement cells, and branching of trichomes. Thus, beyond a role in development, we demonstrate that the class II gene AtTPS6 is important for controlling cellular morphogenesis.