Biological implications of the occurrence of 32 members of the XTH (xyloglucan endotransglucosylase/hydrolase) family of proteins in the bryophyte Physcomitrella patens.
Biological implications of the occurrence of 32 members of the XTH (xyloglucan endotransglucosylase/hydrolase) family of proteins in the bryophyte Physcomitrella patens.
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DOI：
10.1111/j.1365-313x.2010.04351.x
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发表时间：
2010-11
期刊：
影响因子：
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通讯作者：
R. Yokoyama;Yohei Uwagaki;Hiroki Sasaki;T. Harada;Y. Hiwatashi;M. Hasebe;K. Nishitani
中科院分区：
文献类型：
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作者：
R. Yokoyama;Yohei Uwagaki;Hiroki Sasaki;T. Harada;Y. Hiwatashi;M. Hasebe;K. Nishitani
木葡聚糖内切转葡糖基酶/水解酶（XTH）家族的基因和蛋白质在brabrites，基于研究使用的基因组资源，是新的苔藓立碗藓，提供了新的见解植物进化。在被子植物中，XTH基因存在于大型多基因家族中，可能反映了单个XTH在不同细胞类型中的不同作用。由于P. patens中的细胞类型比被子植物如拟南芥和水稻中的细胞类型少，因此很容易推断在bratites中存在较少的XTH家族基因。然而，本研究出乎意料地在展叶侧耳基因组中鉴定出多达32个可能编码XTH家族蛋白的基因，构成了一个相当大的多基因家族，其大小与拟南芥和水稻相当。木葡聚糖内切转葡糖基酶活性在这种苔藓中的原位定位表明，一些P. patens XTH蛋白表现出类似于被子植物中发现的生物化学功能，并且它们的表达谱是组织依赖性的。然而，通过比较展叶连翘和被子植物中XTH基因家族的结构特征，发现存在一些被子植物中没有的、具有独特结构和功能特征的被子植物特有的XTH基因。这些bratite特异性XTH基因可能已经进化以满足bratite特定的形态和功能需求。这些发现提出了有趣的问题，在非种子植物的XTH蛋白质家族的生物学意义。
This comprehensive overview of the xyloglucan endotransglucosylase/hydrolase (XTH) family of genes and proteins in bryophytes, based on research using genomic resources that are newly available for the moss Physcomitrella patens, provides new insights into plant evolution. In angiosperms, the XTH genes are found in large multi-gene families, probably reflecting the diverse roles of individual XTHs in various cell types. As there are fewer cell types in P. patens than in angiosperms such as Arabidopsis and rice, it is tempting to deduce that there are fewer XTH family genes in bryophytes. However, the present study unexpectedly identified as many as 32 genes that potentially encode XTH family proteins in the genome of P. patens, constituting a fairly large multi-gene family that is comparable in size with those of Arabidopsis and rice. In situ localization of xyloglucan endotransglucosylase activity in this moss indicates that some P. patens XTH proteins exhibit biochemical functions similar to those found in angiosperms, and that their expression profiles are tissue-dependent. However, comparison of structural features of families of XTH genes between P. patens and angiosperms demonstrated the existence of several bryophyte-specific XTH genes with distinct structural and functional features that are not found in angiosperms. These bryophyte-specific XTH genes might have evolved to meet morphological and functional needs specific to the bryophyte. These findings raise interesting questions about the biological implications of the XTH family of proteins in non-seed plants.