摘要
以秋菊晚花品种‘金龙腾云’为试材,于不同低温(4、-4℃)条件下分别处理3、6、9、12 h,研究其对叶绿素荧光参数、脂肪酸质量分数的影响。结果表明:-4℃低温处理过程中,CmFAD2表达量9 h达到最高,CmSAD、CmFAD7表达量升高,不饱和脂肪酸质量分数和双键指数(DB,I)值增加,最大光化学效率(Fv/Fm)、潜在光化学效率(Fv/Fo)、光化学猝灭(Qp)呈下降趋势,非光化学猝灭(NP,Q)则先降后升,表明菊花叶片通过降低PSⅡ光能利用率和光化学效率,增加热耗散的方式响应低温胁迫。同一温度下随低温胁迫时间延长Fv/Fm、Qp、NP,Q值变化趋于平稳,叶绿素a质量分数/叶绿素b质量分数随温度降低显著升高,且叶绿素a质量分数/叶绿素b质量分数与亚油酸、亚麻酸、不饱和脂肪酸/饱和脂肪酸及DB,I值呈显著正相关。低温胁迫提高了菊花叶片脂肪酸去饱和酶基因表达量,促使不饱和脂肪酸质量分数增加,进而维持PSⅡ功能相对稳定,为深入阐述菊花低温响应生理机制提供理论基础。
Two low temperatures(4 ℃ and-4 ℃) were set for 3, 6, 9 and 12 h to explore the changes of autumn chrysanthemum cultivar ‘jinlongtengyun’ on chlorophyll fluorescence parameters and fatty acid mass fraction. The expression of CmFAD2 first decreased and then increased, and reached the highest level at 9 h. The expression of CmSAD and CmFAD7 increased, which promoted the increase of unsaturated fatty acid content and DB,I value. Fv/Fm, Fv/Fo and QP all decreased, while NP,Q first decreased and then increased. It indicated that plants increased heat by reducing photosynthetic efficiency and photochemical efficiency of PSⅡ in leaves, while chlorophyll a/chlorophyll b increased significantly with the decrease of temperature, and chlorophyll a/chlorophyll b was positively correlated with linoleic acid, linolenic acid, unsaturated fatty acid/saturated fatty acid and DB,I values. Low temperature stress increased the expression of fatty acid desaturase gene in chrysanthemum leaves, and the content of unsaturated fatty acid increased, thus maintaining the relatively stable PSⅡ function, providing a theoretical basis for further elucidation of the physiological mechanism of chrysanthemum’s low temperature response.
作者
聂林杰
孙泽硕
程祥飞
张开明
李永华
Nie Linjie;Sun Zeshuo;Cheng Xiangfei;Zhang Kaiming;Li Yonghua(Henan Agricultural University,Zhengzhou 450002,P.R.China)
出处
《东北林业大学学报》
CAS
CSCD
北大核心
2020年第11期61-65,共5页
Journal of Northeast Forestry University
基金
河南省科技攻关项目(182102110190)。
关键词
菊花
低温胁迫
脂肪酸去饱和酶基因
叶绿素荧光参数
不饱和脂肪酸
Chrysanthemum
Low temperature stress
Fatty acid desaturase gene
Chlorophyll fluorescence parameters
Unsaturated fatty acid
