PbMC1a/1b regulates lignification during stone cell development in pear (Pyrus bretschneideri) fruit
PbMC1a/1b regulates lignification during stone cell development in pear (Pyrus bretschneideri) fruit
复制标题
PbMC1a/1b 调节梨 (Pyrus bretschneideri) 果实石细胞发育过程中的木质化
DOI：
10.1038/s41438-020-0280-x
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发表时间：
2020-05-01
影响因子：
8.7
通讯作者：
Tao, Shutian
中科院分区：
文献类型：
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作者：
Gong, Xin;Xie, Zhihua;Tao, Shutian
梨果实细胞程序性死亡（PCD）和次生细胞壁（SCW）的增厚伴随着纤维素和木质素的沉积，形成石细胞。Metacaspase是一种重要的蛋白酶，在发育、组织更新和PCD中起重要作用。梨（梨）metacaspase促进PCD和细胞壁木质化的分子机制的理解仍然有限。在这项研究中，Metacaspases基因家族（PbMCs）从P. bretschneideri的鉴定。通过生理数据、半定量实时聚合酶链反应（RT-PCR）和定量RT-PCR（qRT-PCR）分析，PbMC 1a/1b与木质素沉积和石细胞形成相关。相对于野生型（WT）拟南芥，PbMC 1a/1b的过表达增加木质素沉积和延迟生长，增厚导管，木质纤维和束间纤维的细胞壁，并增加木质素生物合成基因的表达。酵母双杂交（Y2 H）、双分子荧光互补（BiFC）和GST pull-down分析表明PbMC 1a/1b蛋白与PbRD 21具有物理相互作用。同时，PbMC 1a/1b和PbRD 21的瞬时表达导致梨果实和果肉愈伤组织中基因表达和木质素含量的显著变化。这些结果表明，PbMC 1a/1b在梨果实细胞壁木质化过程中起重要作用，可能通过与PbRD 21相互作用，提高了一些木质素合成相关基因的mRNA水平，促进了梨果实石细胞的形成。
Programmed cell death (PCD) and secondary cell wall (SCW) thickening in pear fruit are accompanied by the deposition of cellulose and lignin to form stone cells. Metacaspase is an important protease for development, tissue renewal and PCD. The understanding of the molecular mechanism whereby pear (Pyrus) metacaspase promotes PCD and cell wall lignification is still limited. In this study, the Metacaspases gene family (PbMCs) from P. bretschneideri was identified. PbMC1a/1b was associated with lignin deposition and stone cell formation by physiological data, semiquantitative real-time polymerase chain reaction (RT-PCR) and quantitative RT-PCR (qRT-PCR). Relative to wild-type (WT) Arabidopsis, the overexpression of PbMC1a/1b increased lignin deposition and delayed growth, thickened the cell walls of vessels, xylary fibers and interfascicular fibers, and increased the expression of lignin biosynthetic genes. Yeast two-hybrid (Y2H), bimolecular fluorescence complementation (BiFC) and GST pull-down assays indicated that the PbMC1a/1b protein physically interacted with PbRD21. Simultaneously, the transient expression of PbMC1a/1b and PbRD21 led to significant changes in the expression of genes and lignin contents in pear fruits and flesh calli. These results indicate that PbMC1a/1b plays an important role in cell wall lignification, possibly by interacting with PbRD21 to increase the mRNA levels of some lignin synthesis-associated genes and promote the formation of stone cells in pear fruit.