The MPK6-LTF1L1 module regulates lignin biosynthesis in rice through a distinct mechanism from Populus LTF1.
The MPK6-LTF1L1 module regulates lignin biosynthesis in rice through a distinct mechanism from Populus LTF1.
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DOI：
10.1016/j.plantsci.2023.111890
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发表时间：
2023-10
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影响因子：
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通讯作者：
Ping Zhu;Yu Zhong;Laifu Luo;Junhui Shen;Jiayan Sun;Laigeng Li;Longjun Cheng;J. Gui
中科院分区：
文献类型：
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作者：
Ping Zhu;Yu Zhong;Laifu Luo;Junhui Shen;Jiayan Sun;Laigeng Li;Longjun Cheng;J. Gui
木质素是一种复杂的聚合物，为植物提供结构支持和防御。它在特化细胞的次生细胞壁中合成。LTF 1通过调节其稳定性，作为控制双子叶植物杨属木质素生物合成的开关。然而，如何木质素的生物合成调节水稻，单子叶植物，仍然不清楚。通过遗传学、细胞学和化学方法，我们发现LTF 1 L1是LTF 1的水稻同源物，它通过与白杨LTF 1不同的机制调节木质素的生物合成。LTF 1L1基因敲除后，水稻茎厚壁组织细胞中木质素合成增加，而LTF 1L1基因过表达后，木质素合成减少，LTF 1L1被OsMPK 6磷酸化，但不影响其稳定性，但抑制木质素合成相关基因表达的能力减弱。LTF 1L1的非磷酸化突变体（LTF 1L1S169A）对水稻和杨树的木质素生物合成都有较强的抑制作用。我们的研究结果表明，LTF 1L1作为一个负调控木质素生物合成的机制，从LTF 1在杨属和突出的进化多样性在木质素生物合成的调控。
Lignin is a complex polymer that provides structural support and defense to plants. It is synthesized in the secondary cell walls of specialized cells. Through regulates its stability, LTF1 acts as a switch to control lignin biosynthesis inPopulus, a dicot plant. However, how lignin biosynthesis is regulated in rice, a monocot plant, remains unclear. By employing genetic, cellular, and chemical approaches, we discovered thatLTF1L1, a rice homolog ofLTF1, regulates lignin biosynthesis through a distinct mechanism fromPopulusLTF1. Knockout ofLTF1L1increased lignin synthesis in the sclerenchyma cells of rice stems, while overexpression ofLTF1L1decreased it. LTF1L1 is phosphorylated by OsMPK6 at Ser169, which did not affect its stability but impaired its ability to repress the expression of lignin biosynthesis genes. This was supported by the non-phosphorylated mutant of LTF1L1 (LTF1L1S169A), which displayed a stronger repressive effect on lignin biosynthesis in both rice andPopulus. Our findings reveal thatLTF1L1acts as a negative regulator of lignin biosynthesisviaa distinct mechanism from that of LTF1 inPopulusand highlight the evolutionary diversity in the regulation of lignin biosynthesis in plants.