The Arabidopsis XET-related gene family: environmental and hormonal regulation of expression.
The Arabidopsis XET-related gene family: environmental and hormonal regulation of expression.
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DOI：
10.1046/j.1365-313x.1996.9060879.x
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发表时间：
1996-06
期刊：
影响因子：
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通讯作者：
Wei Xu;Paul Campbell;Ajay K. Vargheese;J. Braam
中科院分区：
文献类型：
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作者：
Wei Xu;Paul Campbell;Ajay K. Vargheese;J. Braam
修饰细胞壁组分的酶很可能在改变植物细胞的大小、形状和物理性质方面发挥关键作用。这种修饰活性的调节在形态发生过程中以及在引起响应环境条件而产生的发育和生理变化中是重要的。先前的工作已经表明，拟南芥TCH 4基因编码木葡聚糖内糖基转移酶（XET），其作用于植物细胞壁的主要半纤维素。TCH 4的表达在几种环境刺激（包括触摸、风、黑暗、热休克和冷休克）以及生长促进激素、生长素和油菜素类固醇的反应中显著上调。本文报道了拟南芥中存在一个广泛的XET相关基因家族。除了TCH 4，这个家族还包括两个先前鉴定的基因，EXT和Meri-5，以及至少五个额外的基因。XTR家族的cDNA共享46%至79%的序列同一性，并且预测的XTR蛋白共享37%至84%的同一性。所有八种蛋白质都包括潜在的N-末端信号序列，并且大多数具有保守基序（DEIDFEFLG），该基序也在芽孢杆菌β-葡聚糖酶中发现，并且可能对酶活性很重要。XTR基因家族的成员对环境和激素刺激的敏感性不同。调节的幅度和动力学对于不同的基因是不同的。这个复杂的基因家族表达的差异调节表明相关的，但不同的，细胞壁修饰酶，可以控制细胞壁和组织的特性，在发展过程中，并响应于环境的线索招聘。
Enzymes that modify cell wall components most likely play critical roles in altering size, shape, and physical properties of plant cells. Regulation of such modifying activity is expected to be important during morphogenesis and in eliciting developmental and physiological alterations that arise in response to environmental conditions. Previous work has shown that the Arabidopsis TCH4 gene encodes a xyloglucan endotransglycosylase (XET) which acts on the major hemicellulose of the plant cell wall. The expression of TCH4 is dramatically upregulated in response to several environmental stimuli (including touch, wind, darkness, heat shock, and cold shock) as well as the growth-enhancing hormones, auxin and brassinosteroids. This paper reports the presence of an extensive XET-related (XTR) gene family in Arabidopsis. In addition to TCH4, this family includes two previously identified genes, EXT and Meri-5, and at least five additional genes. The cDNAs of the XTR family share between 46 and 79% sequence identity and the predicted XTR proteins share from 37 to 84% identity. All eight proteins include potential N-terminal signal sequences and most have a conserved motif (DEIDFEFLG) that is also found in Bacillus beta-glucanase and may be important for enzyme activity. The members of the XTR gene family are differentially sensitive to environmental and hormonal stimuli. Magnitude and kinetics of regulation are distinct for the different genes. Differential regulation of expression of this complex gene family suggests a recruitment of related, yet distinct, cell wall-modifying enzymes that may control the properties of cell walls and tissues during development and in response to environmental cues.