摘要
【目的】棉花作为一种重要的经济作物和油料作物,其叶片和纤维均可积累色素物质,呈现不同颜色。叶绿素、类胡萝卜素和花青素的含量及其比例是棉花叶片呈色的主要原因,而棕色纤维中主要色素成分为花青素单体氧化聚合而成的原花青素及其衍生物。通过分析陆地棉不同的叶色突变体叶片和纤维中的花青素含量,花青素和原花青素合成途径中关键基因的表达,探究棉花叶片和纤维颜色呈现与花青素合成的关系,为叶色突变体的利用和彩色棉纤维色泽的改良奠定基础。【方法】通过测定21个陆地棉叶色突变体的叶片花青素含量,根据叶色突变体叶片、纤维颜色和花青素含量差异,筛选了其中6个典型的棉花叶色突变体作为研究材料,比较叶片和纤维(开花后15 d)中的花青素含量,分析花青素含量与叶片、纤维颜色呈现的关系;同时检测叶片及不同发育时期纤维(开花后5、10、15和20 d)中花青素合成关键基因GhCHS和原花青素合成途径关键基因GhLAR和GhANR的表达水平,分析目标基因对叶片和纤维颜色呈现的影响。【结果】21个陆地棉叶色突变体叶片中的花青素含量差异显著,呈现紫红色或紫色的叶片花青素含量高。在筛选的6个陆地棉叶色突变体及其对照叶片和不同发育时期纤维中,叶片花青素含量显著高于纤维,棕色纤维的花青素含量显著高于白色纤维。叶片中,GhCHS表达量较高,而GhANR和GhLAR表达量较低,花青素积累与颜色呈现与其表达量没有显著的相关性;而在纤维中,GhANR和GhLAR在棕色纤维的表达量极显著高于白色纤维中,且主要集中在纤维发育的5—15 DPA高表达。【结论】陆地棉叶片和纤维的颜色呈现均与花青素含量有关,紫色及紫红色叶片以及棕色纤维中花青素含量高,但纤维颜色的形成与棉花叶片颜色呈现没有显著的相关性,其花青素含量与原花青素合成途径的关键基因GhANR和GhLAR表达水平直接相关,表明棉花叶片和纤维中的呈色机制不一致,原花青素主要在纤维中积累显色。
【Objective】Cotton is an important economic and oil crop.Both its leaves and fibers can accumulate pigments and present different colors.Studies have confirmed that chlorophyll,carotenoids,and anthocyanin are the main pigments in cotton leaves and their relative proportion changes leaf colors.While proanthocyanidins and their derivatives,which are oligomeric and polymeric products from anthocyanidins,are thought to be responsible for the color formation of brown fibers.This article intends to explore the relationship between the color of leaves and fibers in upland cotton through analyzing the anthocyanidin content and gene expression level in the anthocyanin biosynthesis pathway in different leaf color mutants.The result will help to lay the foundation for the utilization of leaf color mutants and the improvement of the color of colored cotton fibers.【Method】In this experiment,the anthocyanidin contents in leaves of 21 upland cotton leaf color mutants were detected.According to the leaf and fiber color as well as the anthocyanidin content level,6 cotton leaf color mutants were selected as materials to measure the anthocyanidin level in leaves and fibers at 15 days post anthesis to analyze the relationship between anthocyanidin content and the leaf or fiber color.Then the expression levels of Gh CHS,GhLAR and Gh ANR in leaves and fibers at different developmental stages(5,10,15,20 DPA)were measured to analyze the influence of target genes on the color formation of leaves and fibers.【Result】The anthocyanidin content in the leaves of 21 leaf color mutants of G.hirsutum was significantly different,and the purple or fuchsia leaves had higher anthocyanidin content.In the selected six leaf color mutants,the anthocyanidin content in leaves was significantly higher than that in fibers,and brown fibers accumulated more anthocyanidins than white fibers.Compared to Gh CHS,Gh ANR and GhLAR expressed at a very low level in leaves,and no significant correlation was found between leaf color and their expression level.While in fibers,the expressions of GhANR and GhLAR were obviously higher in brown fibers than in white fibers,especially in fibers of 5 DPA to 15 DPA.【Conclusion】Anthocyanins played important roles in color formation of both leaves and fibers in upland cotton.Purple-red or purple leaves and brown fibers accumulated more anthocyanidins,while the formation of fiber color did not directly correlate with leaf color.In fibers,the contents of anthocyanidins directly related to the expression levels of GhANR and Gh LAR,indicating that coloration mechanism of cotton leaves and fibers was not exactly the same,and proanthocyanidins mainly accumulated in fibers.
作者
袁景丽
郑红丽
梁先利
梅俊
余东亮
孙玉强
柯丽萍
YUAN JingLi;ZHENG HongLi;LIANG XianLi;MEI Jun;YU DongLiang;SUN YuQiang;KE LiPing(School of Life Sciences and Medicine,Zhejiang Sci-Tech University/Plant Genomics&Molecular Improvement of Colored Fiber Lab,Hangzhou 310018)
出处
《中国农业科学》
CAS
CSCD
北大核心
2021年第9期1846-1855,共10页
Scientia Agricultura Sinica
基金
国家自然科学基金(U1903204,31671738)
浙江省自然科学基金(LZ21C130004)。
关键词
陆地棉
叶色突变体
纤维色泽
花青素
基因表达
Gossypium hirsutum L.
leaf color mutant
fiber color
anthocyanin
gene expression
