Gibberellin and auxin signals control scape cell elongation and proliferation in Agapanthus praecox ssp orientalis
Gibberellin and auxin signals control scape cell elongation and proliferation in Agapanthus praecox ssp orientalis
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赤霉素和生长素信号控制东方百子莲花细胞的伸长和增殖
DOI：
10.1007/s12374-016-0056-x
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发表时间：
2016
影响因子：
2.9
通讯作者：
Shen Xiao-hui
中科院分区：
文献类型：
--
作者：
Yue Jian-hua;Zhang Di;Ren Li;Shen Xiao-hui
植物的高度是由细胞的增殖和伸长过程决定的。植物激素在这些过程中以物种依赖的方式发挥关键作用。采用400 mg·L-1多效唑（PAC）对百子莲（Agapanthus praecoxssp. orientalis）进行喷雾处理，诱导其花序茎矮化。形态学观察结果表明，与对照相比，PAC抑制了花茎细胞伸长54.56%，抑制了细胞增殖10.45%，从而降低了花茎高度。内源赤霉素（GA）和吲哚乙酸（IAA）的定量和免疫定位结果表明，GA_1、GA_3和GA_4的含量和IAA的梯度降低。其中，GA_4是花茎中GA_4的主要成分，其含量比对照降低了59.51%~ 92.01%。细胞壁合成相关基因纤维素合成酶（CESA）和UDP-葡萄糖醛酸脱羧酶（UXS）的表达显著上调，而细胞壁疏松基因木葡聚糖内切转葡萄糖基酶2（XET 2）的表达下调达99.99%。相关分析表明，GA调节细胞伸长，生长素调节细胞增殖。此外，糖的积累在细胞壁合成和细胞扩展中起作用。这些结果表明，在花葶伸长过程中，GA和IAA信号触发了下游信号级联反应，控制了细胞的扩展和增殖。
Plant height is determined by the processes of cell proliferation and elongation. Plant hormones play key roles in a species-dependent manner in these processes. We used paclobutrazol (PAC) at 400 mg·L-1in this study to sprayAgapanthus praecoxssp.orientalisplants in order to induce dwarf scape (inflorescence stem). Morphological examination showed that PAC reduced scape height by inhibiting the cell elongation by 54.56% and reducing cell proliferation by 10.45% compared to the control. Quantification and immunolocalization of endogenous gibberellins (GAs) and indole-3-acetic acid (IAA) showed that the GA1, GA3, and GA4levels and the IAA gradient were reduced. Among these hormones, GA4 was the key component of GAs, which decreased 59.51-92.01% compared to the control in scape. The expression of cell wall synthesis related genes cellulose synthase (CESA) and UDP-glucuronic acid decarboxylase (UXS) were upregulated significantly, whereas cell wall loosening gene xyloglucan endotransglucosylase 2 (XET2) was downregulated by 99.99% surprisingly. Correlation analysis suggested GA regulated cell elongation and auxin modulated cell proliferation inAgapanthusscape. Additionally, the accumulation of sugars played roles in cell wall synthesis and cell expansion. These results indicated GA and IAA signals triggered a downstream signaling cascade, controlled cell expansion and proliferation during scape elongation.