Homologues of the Arabidopsis thaliana SHI/STY/LRP1 genes control auxin biosynthesis and affect growth and development in the moss Physcomitrella patens
Homologues of the Arabidopsis thaliana SHI/STY/LRP1 genes control auxin biosynthesis and affect growth and development in the moss Physcomitrella patens
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DOI：
10.1242/dev.039594
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发表时间：
2010-04-15
期刊：
影响因子：
4.6
通讯作者：
Sundberg, Eva
中科院分区：
文献类型：
--
作者：
Eklund, D. Magnus;Thelander, Mattias;Sundberg, Eva
植物激素生长素在维管植物中起着重要作用。虽然外源生长素也刺激非维管植物的发育转变和生长，但操纵内源生长素水平的影响迄今尚未报道。在这里，我们已经改变了生长素的生产和积累的苔藓立碗藓通过改变拟南芥SHI/STY家族蛋白，这是生长素生物合成基因的正调节剂的同源物的表达水平和网站。PpSHI 1的组成型表达导致生长素水平升高，生长素反应报告GmGH 3 pro：GUS的增加和异位表达，以及茎丝/绿丝比例增加，外源生长素应用也诱导了这种效果。此外，我们观察到异位表达PpSHI 1的细胞过早老化和坏死。敲除两个PpSHI基因中的任何一个导致叶芽中生长素水平和生长素生物合成速率降低，节间伸长减少，衰老延迟，茎丝/绿丝比例降低和腋毛数量增加，这些构成潜在的生长素生物合成位点。一些鉴定的生长素功能似乎在维管和非维管植物中是类似的。此外，时空表达的PpSHI基因和GmGH 3 pro：GUS强烈重叠，表明当地生长素的生物合成是重要的生长素峰的形成在非维管植物的调节。
The plant hormone auxin plays fundamental roles in vascular plants. Although exogenous auxin also stimulates developmental transitions and growth in non-vascular plants, the effects of manipulating endogenous auxin levels have thus far not been reported. Here, we have altered the levels and sites of auxin production and accumulation in the moss Physcomitrella patens by changing the expression level of homologues of the Arabidopsis SHI/STY family proteins, which are positive regulators of auxin biosynthesis genes. Constitutive expression of PpSHI1 resulted in elevated auxin levels, increased and ectopic expression of the auxin response reporter GmGH3pro:GUS, and in an increased caulonema/chloronema ratio, an effect also induced by exogenous auxin application. In addition, we observed premature ageing and necrosis in cells ectopically expressing PpSHI1. Knockout of either of the two PpSHI genes resulted in reduced auxin levels and auxin biosynthesis rates in leafy shoots, reduced internode elongation, delayed ageing, a decreased caulonema/chloronema ratio and an increased number of axillary hairs, which constitute potential auxin biosynthesis sites. Some of the identified auxin functions appear to be analogous in vascular and non-vascular plants. Furthermore, the spatiotemporal expression of the PpSHI genes and GmGH3pro:GUS strongly overlap, suggesting that local auxin biosynthesis is important for the regulation of auxin peak formation in non-vascular plants.