木质素除了在植物正常生长发育过程中发挥重要功能外，还是细胞壁转化利用的关键影响因子。先前我们在重要能饲两用作物柳枝稷中发现，miR156靶基因PvSPLs表达水平的改变能够显著影响木质素的合成，然而其具体的调控机制尚不清楚。因此本项目拟鉴定能直接调控木质素合成关键酶基因表达的miR156-targeted PvSPLs转录因子的功能，并在此基础上筛选鉴定1-2个与该PvSPLs相互作用影响木质素关键酶基因表达的蛋白因子，研究其对柳枝稷木质素合成的影响。通过上述木质素合成调控新机制的解析，并结合先前改变PvSPL表达影响柳枝稷生物量的研究，有望将细胞壁品质与生物量两个重要性状的遗传改良通过PvSPL单个基因实现统一，从而不但促进高生物量高细胞壁转化利用的能源草和牧草等特色作物的遗传育种，还能够为植物生长发育与木质素合成之间的精准调控提供新思路。

Lignin is a crucial factor controlling plant growth and development. However, the presence of lignin in plant cell wall can negatively impact the utilization of lignocellulosic biomass. Switchgrass (Panicum virgatum L.) is C4 perennial tall grass which can provide substantial feedstock for biofuel production and cattle feed. SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) transcription factor is a target of miR156. Our previous studies have shown that miR156-targeted PvSPLs were involved in lignin biosynthesis, whereas the regulation and molecular mechanism of these PvSPLs has yet to be investigated. Therefore, we propose here to address how the miR156-targeted PvSPLs regulate expression levels of lignin biosynthesis genes directly. Meanwhile, we try to characterize one to two protein factors that interact with PvSPLs and regulate the expression of lignin genes. Our work will elucidate a novel regulation mechanism of lignin biosynthesis mediated by miR156 targeted PvSPLs. The candidate PvSPL and its interacting partners can be used to improve the digestion of cell walls of bioenergy and forage crops. Moreover, our studies will open up new avenue for exploring the potential molecular mechanism that regulate both plant growth and lignin biosynthesis precisely.