Exogenous GA3 application altered morphology, anatomic and transcriptional regulatory networks of hormones in Eucalyptus grandis
Exogenous GA3 application altered morphology, anatomic and transcriptional regulatory networks of hormones in Eucalyptus grandis
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外源 GA3 的应用改变了巨桉激素的形态、解剖和转录调控网络
DOI：
10.1007/s00709-018-1218-0
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发表时间：
2018-07-01
期刊：
影响因子：
2.9
通讯作者：
Fan, Chun-Jie
中科院分区：
文献类型：
--
作者：
Liu, Qian-Yu;Guo, Guang-Sheng;Fan, Chun-Jie
赤霉素（GAs）在植物生长发育中起着重要作用，包括细胞伸长、细胞扩增和木质部分化。桉树是世界上种植最广泛的硬木树，提供纤维和能源。然而，GA在桉树中的作用仍不清楚，其对木质部发育的影响仍有待确定。在本研究中，E.用0.10 mg L-1 GA（3）和/或多效唑（PAC，GA抑制剂）处理grandis植株。记录地上部和根的生长，用甲苯胺蓝对根和茎的横切面进行染色，并通过定量实时PCR分析与激素反应和次生细胞壁生物合成相关的基因的表达水平。结果表明，GA（3）显著促进了根长和地上部长度的增长，但降低了根粗和茎粗。外源GA（3）处理也显著促进了茎和根木质部的发育。表达分析表明，外源GA（3）的应用改变了基因的转录水平的GA生物合成途径和GA信号，以及相关基因的生长素，细胞分裂素，和次生细胞壁。这些结果表明，GAs可能与其他激素（如生长素和细胞分裂素）的相互作用，以调节次生细胞壁生物合成基因的表达，并触发桉树植物的木质化。
Gibberellins (GAs) play a key role in plant growth and development including cell elongation, cell expansion, and xylem differentiation. Eucalyptus are the world's most widely planted hardwood trees providing fiber and energy. However, the roles of GAs in Eucalyptus remain unclear and their effects on xylem development remain to be determined. In this study, E. grandis plants were treated with 0.10 mg L-1 GA(3) and/or paclobutrazol (PAC, a GA inhibitor). The growth of shoot and root were recorded, transverse sections of roots and stems were stained using toluidine blue, and expression levels of genes related to hormone response and secondary cell wall biosynthesis were analyzed by quantitative real-time PCR. The results showed that GA(3) dramatically promoted the length of shoot and root, but decreased the diameter of root and stem. Exogenous GA(3) application also significantly promoted xylem development in both stem and root. Expression analysis revealed that exogenous GA(3) application altered the transcript levels of genes related to the GA biosynthetic pathway and GA signaling, as well as genes related to auxin, cytokinin, and secondary cell wall. These findings suggest that GAs may interact with other hormones (such as auxin and cytokinin) to regulate the expression of secondary cell wall biosynthesis genes and trigger xylogenesis in Eucalyptus plants.