草原龙胆高温诱导莲座化的代谢组学分析

Metabolomics analyses of Eustoma grandiflorum rosette induced by high temperature

为揭示高温引起草原龙胆莲座化的代谢机制,采用气相色谱-质谱法(GC-MS)结合代谢组学分析技术,研究常温和高温处理下草原龙胆成熟叶片和茎尖的代谢差异。共鉴定出30种代谢产物,偏最小二乘法判别分析显示不同温度下和不同组织中的代谢物均得到很好的分离。方差分析表明,与常温处理相比,高温下草原龙胆茎尖中的糖类含量降低,有机酸含量升高,而成熟叶片内的变化趋势刚好相反。推测草原龙胆在高温胁迫下茎尖的糖类含量下降可能导致其发生莲座化,从而无法正常抽薹开花;而成熟叶片中增加的可溶性糖有利于提高植株的渗透保护能力,从而抵抗非生物逆境。在不同组织间,高温下的差异明显小于常温下代谢物的差异。推测常温下茎尖与成熟叶较大的差异体现了异质性的发育趋势,而高温下组织间差异的缩小体现了机体共同应对胁迫的系统防御机制。

To explore the metabolicmechanisms of rosette induced by high temperature,GC-MS was used to study metabolic differences in mature leaves and shoot tips of Eustoma grandia4lorum under normal （22 ℃） and high （30℃） temperatures.Thirty metabolites were identified and results of the PLS-DA analyses of them showed that the metabolites in different organs under different temperatures were sepa- rated clearly.Analyses of variance showed that many sugars were decreased and organic acids increased significantly in shoot tips under the high temperature compared with that under the normal temperature. The case in mature leaveswas completely opposite.It is indicated that under the high temperature, the de- crease of sugars in shoot apex caused the rosette,while the accumulation of sugars in mature leaves improved the stress resistance of Eustoma grandiflorurn. The metabolite difference between mature leaf and shoot tip under the high temperature is less than that under the normal temperature.It is suggested that the larger difference under the normal temperature shows the different development direction between leaf and shoot,while the smaller difference implies the systematic mechanism of Eustoma grandi- florurn in response to abiotic stress.