RNA sequencing reveals the dynamic carbohydrate metabolism and phytohormone signaling accompanying post-mowing regeneration of forage winter wheat (Triticum aestivum L.)

In northern China, wheat has been widely grown for grain production, but is rarely used for forage production. In contrast, the fresh green forage in winter in northern China is scarce and needs to be imported from abroad. The use of dual purpose wheat can alleviate the lack of fresh green forage, while improving soil use efficiency as the lack of cultivated land in China. The regeneration of winter wheat has important practical significance for maintaining nutrient accumulation of wheat seedling after cutting, and will eventually affect the spring elongation and summer grain harvest of wheat. This is also a key factor in determining whether wheat can be used for dual purpose. In this study, we identified differentially expressed mRNAs and long chain non coding RNAs (lncRNAs) and systematically demonstrated the molecular responses of mRNAs and lncRNAs during the post mowing regeneration of wheat cultivar XN9106, which was cultivated for forage and grain production in winter and summer separately. The result showed degraded carbohydrate and enhanced photosynthesis provide energy and material base for cell proliferation and expansion during regeneration of mowed wheat. Enhanced auxin and cytokinin signaling and inhibited ABA signaling regulated the post mowing regeneration. Furthermore, 21 differentially expressed lncRNAs regulated the differential expression of key genes related to carbohydrate metabolism, photosynthesis, and phytohormone signaling, indicating the potential role of lncRNAs in the post mowing regeneration. The key finding of this study is that carbohydrate and phytohormone participated in post-mowing regeneration of wheat and lncRNA plays an important role in this process, which will guide us to breed wheat varieties with higher sugar content in the stubble and develop external reagents promoting forage regeneration.