石榴种皮总木质素含量及PgCOMT基因的克隆与表达

摘要

为探讨石榴(Punica granatumL.)籽粒硬度与种皮总木质素含量的相关性及种皮COMT基因的表达方式，利用Texture Analyser质构仪和巯基乙酸法测定6个品种的成熟籽粒硬度及种皮总木质素含量。结果表明，6个石榴品种的籽粒硬度与种皮总木质素含量呈正相关，相关系数为0.9246。采用RACE技术从石榴种皮中克隆得到1条长度为1456 bp的PgCOMT基因cDNA序列(GenBank登录号为KJ713968)。实时荧光定量PCR分析表明，PgCOMT在‘红玉石籽’、‘粉皮’、‘会理软籽’、‘蒙自甜’和‘突尼斯软籽’石榴种皮中的相对表达量与石榴籽粒硬度较为一致；随着石榴种皮的发育其表达量先下降后上升。这为深入了解石榴软籽性状的产生机理奠定了基础。%In order to understand the correlation between seed hardness and total lignin content in seed coat of pomegranate (Punica granatum), the seed hardness and total lignin content of six cultivars were measured by Texture Analyser and thioglycolic acid method. The results showed that the correlation coefifcient was 0.9246 between seed hardness and total lignin content in seed coat. A full-length cDNA sequence of 1456 bp (GenBank accession No.: KJ713968) was cloned from pomegranate seed coat by RACE, namedPgCOMTgene. Real-time quantitative PCR showed that the relative expression ofPgCOMTin ‘Hongyushizi’, ‘Fenpi’, ‘Huiliruanzi’, ‘Mengzitian’ and ‘Tunisiruanzi’ seed coat had a similar trend with seed hardness. The relative expression of PgCOMTdeclined at ifrst, and then rose with development stage of pomegranate seed coat the last stage. These lay a foundation for further study the mechanism of soft seed traits in pomegranate.