Functional analysis of complexes with mixed primary and secondary cellulose synthases Functional analysis of complexes with mixed primary and secondary cellulose synthases
Functional analysis of complexes with mixed primary and secondary cellulose synthases Functional analysis of complexes with mixed primary and secondary cellulose synthases
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DOI：
10.4161/psb.23179
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发表时间：
2013-01-01
影响因子：
2.9
通讯作者：
Gu, Ying
中科院分区：
文献类型：
--
作者：
Li, Shundai;Lei, Lei;Gu, Ying
在高等植物中，纤维素是由纤维素合酶复合物合成的，该复合物含有多种纤维素合酶（CESAs）的同工型。在拟南芥共有的10个CESA基因中，有3个基因（irx1（cesa8）、irx3（cesa7）和irx5(cesa4)）发生隐性突变，导致拟南芥花序茎成熟木质部细胞塌陷。这些CESA基因被认为是次生细胞壁CESA。其他的（CESA10的功能尚不清楚）被认为专门用于原代细胞壁的纤维素合成。采用分裂-泛素膜酵母双杂交系统，对4个一级CESAs （CESA1、CESA2、CESA3、CESA6）和3个二级CESAs （CESA4、CESA7、CESA8）之间的相互作用进行了评价。我们的研究结果表明，初级CESAs可以以有限的方式与次级CESAs进行物理相互作用。转基因株系分析表明，CESA1能部分挽救irx1（cesa8）零突变体，弥补植株生长缺陷、木质部萎缩和纤维素含量不足。这些结果表明，混合初级和次级CESA配合物在实验设置下是功能性的。
In higher plants, cellulose is synthesized by cellulose synthase complexes, which contain multiple isoforms of cellulose synthases (CESAs). Among the total 10 CESA genes in Arabidopsis, recessive mutations at three of them cause the collapse of mature xylem cells in inflorescence stems of Arabidopsis (irx1(cesa8), irx3(cesa7) and irx5(cesa4)). These CESA genes are considered secondary cell wall CESAs. The others (the function CESA10 is still unknown) are thought to be specialized for cellulose synthesis in the primary cell wall. A split-ubiquitin membrane yeast two-hybrid system was used to assess interactions among four primary CESAs (CESA1, CESA2, CESA3, CESA6) and three secondary CESAs (CESA4, CESA7, CESA8). Our results showed that primary CESAs could physically interact with secondary CESAs in a limited fashion. Analysis of transgenic lines showed that CESA1 could partially rescue irx1(cesa8) null mutants, resulting in complementation of the plant growth defect, collapsed xylem and cellulose content deficiency. These results suggest that mixed primary and secondary CESA complexes are functional using experimental set-ups.