Plant Gene Expression Lab, CSIR-National Botanical Research Institute (CSIR), Lucknow, 226001, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
Plant Gene Expression Lab, CSIR-National Botanical Research Institute (CSIR), Lucknow, 226001, India.
Plant Sci. 2019 Mar;280:330-339. doi: 10.1016/j.plantsci.2018.12.013. Epub 2018 Dec 18.
The fragrant rose, Rosa bourboniana, is highly sensitive to ethylene and shows rapid petal abscission (within 16-18 h) while the non-fragrant hybrid rose, R. hybrida, shows delayed abscission (50-52 h) due to reduced ethylene sensitivity. To understand the molecular basis governing these differences, all components of the ethylene pathway (biosynthesis/ receptor/signalling) were studied for expression during abscission. Transcript accumulation of most ethylene biosynthesis genes (ACS/ACO families) increased rapidly in petal abscission zones of R. bourboniana within 4-8 h of ethylene treatment. The expression of most receptor and signalling genes encoding CTRs, EIN2 and EIN3/EIL homologues also followed similar kinetics. Under natural field conditions where abscission takes longer, there was a temporal delay in transcript accumulation of most ethylene pathway genes while some biosynthesis genes (showing reduced ethylene sensitivity) were more strongly up-regulated by abscission cues. In contrast, in R. hybrida where even ethylene-induced abscission is considerably delayed, transcript accumulation of most ethylene biosynthesis and signalling genes was, surprisingly, reduced by ethylene and showed an opposite regulation compared to R. bourboniana. The results suggest that differential and reciprocal regulation of ethylene pathway is one of the major reasons for differences in petal abscission and vase-life between Rosa bourboniana and R. hybrida.
芳香的玫瑰 Rosa bourboniana 对乙烯非常敏感，表现出快速的花瓣脱落（在 16-18 小时内），而无香味的杂交玫瑰 R. hybrida 由于乙烯敏感性降低，表现出延迟的脱落（50-52 小时）。为了了解控制这些差异的分子基础，研究了乙烯途径（生物合成/受体/信号转导）的所有成分在脱落过程中的表达情况。在乙烯处理后 4-8 小时内，R. bourboniana 花瓣脱落区中大多数乙烯生物合成基因（ACS/ACO 家族）的转录物积累迅速增加。编码 CTRs、EIN2 和 EIN3/EIL 同源物的大多数受体和信号转导基因的表达也遵循类似的动力学。在自然田间条件下，脱落时间较长，大多数乙烯途径基因的转录物积累存在时间延迟，而一些生物合成基因（表现出降低的乙烯敏感性）则被脱落信号更强烈地上调。相比之下，在乙烯诱导的脱落也明显延迟的 R. hybrida 中，大多数乙烯生物合成和信号转导基因的转录物积累却被乙烯降低，与 R. bourboniana 的调控相反。研究结果表明，乙烯途径的差异和相互调节是 Rosa bourboniana 和 R. hybrida 花瓣脱落和瓶插寿命差异的主要原因之一。
