Cryptochrome-mediated blue-light signal contributes to lignin biosynthesis in stone cells in pear fruit.
Cryptochrome-mediated blue-light signal contributes to lignin biosynthesis in stone cells in pear fruit.
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DOI：
10.1016/j.plantsci.2022.111211
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发表时间：
2022-02
期刊：
影响因子：
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通讯作者：
Qi Wang;Xin Gong;Z. Xie;K. Qi;Kaili Yuan;Yuru Jiao;Q. Pan;Shaoling Zhang;K. Shiratake
中科院分区：
文献类型：
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作者：
Qi Wang;Xin Gong;Z. Xie;K. Qi;Kaili Yuan;Yuru Jiao;Q. Pan;Shaoling Zhang;K. Shiratake
光环境是植物整个生活史中包括果实发育在内的众多发育过程中不可缺少的调节因子。石细胞由于其强烈的木质化细胞壁而对梨果实品质产生负面影响，但光质如何影响梨木质素的生物合成尚不清楚。欧洲梨（PyruscommunisL.）采用不同光照处理的石细胞，观察石细胞表型、木质素含量和H2 O2含量的变化，并结合RNA-Seq和qRT-PCR技术，探讨光照对石细胞木质素生物合成的可能调控途径。结果表明，蓝光处理增加了木质素结构基因的表达，促进了木质素的积累。此外，在白色梨中还鉴定出4种蓝光受体隐花色素，分别命名为PbO 1a（Pbr 024556.1）、PbO 1b（Pbr 001636.3）、PbO 2a（Pbr 023037.1）和PbO 2b（Pbr 002655.4）。qRT-PCR分析表明，PbCl_1在石细胞含量高的品种中高表达。此外，通过梨愈伤组织的遗传转化和根癌农杆菌介导的梨幼果中的瞬时过表达，证实了PbO 1a在梨果实石细胞形成中的分子功能。利用RNA-seq数据的共表达网络分析表明，在蓝光条件下，8个MYB基因和5个NAC基因与木质素生物合成基因被分为不同的共表达簇。这些结果表明，蓝光信号在梨细胞壁木质化过程中起重要作用，并通过调控下游基因促进石细胞的形成。
Light environment is an indispensable factor that regulates multitudinous developmental processes during the whole life cycle of plants, including fruit development. Stone cells which negatively influence pear fruit quality because of their strongly lignified cell wall are also affected by light, however, how light qualities influence lignin biosynthesis in pear remains unclear. Here, the calli of European pear (PyruscommunisL.) treated with different lights were used to explore the changes in phenotype, lignin content, and H2O2content, coupled with RNA-Seq and quantitative real-time PCR (qRT-PCR) to investigate the possible regulation pathway of light on lignin biosynthesis in stone cells. Results showed that blue light increased the expression of lignin structure genes and promoted lignin accumulation. Besides, four blue light receptors cryptochromes (CRYs) were identified in white pear, namedPbCRY1a(Pbr024556.1),PbCRY1b(Pbr001636.3),PbCRY2a(Pbr023037.1), andPbCRY2b(Pbr002655.4). qRT-PCR analysis showed thatPbCRY1ais highly expressed in cultivars with a high content of stone cells. Furthermore, the molecular function ofPbCRY1aon stone cell formation in pear fruit was demonstrated by genetic transformation of pear calli and Agrobacterium-mediated transient overexpression in pear fruitlets. Co-expression network analyses with RNA-seq data showed that 8 MYB and 5 NAC genes were classified into different co-expression clusters with lignin biosynthesis genes under blue light conditions. These results indicate that CRY-mediated blue-light signal plays an important role in cell wall lignification and promotes the formation of stone cells in pear by regulating downstream genes.