Sudan grass is a high-quality forage of sorghum. The degree of lignification of Sudan grass is the main factor affecting its digestibility in ruminants such as cattle and sheep. Almost all lignocellulose in Sudan grass is stored in the secondary cell wall, but the mechanism and synthesis of the secondary cell wall in Sudan grass is still unclear. In order to study the mechanism of secondary cell wall synthesis in Sudan grass, we used an in vitro induction system of Sudan grass secondary cell wall. Through transcriptome sequencing, it was found that the NAC transcription factor CcNAC1 gene was related to the synthesis of the Sudan grass secondary cell wall. This study further generated CcNAC1 overexpression lines of Arabidopsis to study CcNAC1 gene function in secondary cell wall synthesis. It was shown that the overexpression of the CcNAC1 gene can significantly increase lignin content in Arabidopsis lines. Through subcellular localization analysis, CcNAC1 genes could be expressed in the nucleus of a plant. In addition, we used yeast two-hybrid screening to find 26 proteins interacting with CcNAC1. GO and KEGG analysis showed that CcNAC1 relates to the metabolic pathways and biosynthesis of secondary metabolites. In summary, the synthesis of secondary cell wall of Sudan grass can be regulated by CcNAC1.
Researchers have reported that Bacillus megaterium BM18-2 reduces Cd toxicity in Hybrid Pennisetum, but understanding the interaction between plants and associated endophytes is crucial for understanding phytoremediation strategies under heavy metal stress. The current study aims to monitor the colonization patterns of GFP-labeled endophytic bacteria BM18-2 on Hybrid Pennisetum grass. Additionally, it will monitor Cd’s effect on plant bacterial colonization. Confocal laser scanning microscopy of plant roots infected with gfp tagged BM18-2 revealed that the bacterium colonised root hairs and epidermal cells at the early stage of colonization, and over time, the bacteria penetrated to the internal tissues following their colonization of the stem and leaf. The roots, stems, and leaves of H. Pennisetum grown in Cd-contaminated soil contained a higher number of bacteria than those grown in normal soil. The result of Cd translocation indicated the condensation of heavy metals in the root cells and stem, while no Cd was found in the leaf. The study will also look for the enzymatic activity of bacteria BM18-2 and use Leadmium Green AM dye to track how Cd is taken up and moved through the plant. The enzymatic activity results showed that BM18-2 can produce catalase and amylase, but did not record any cellulase or lipase activity. As a result, the pattern of useful endophytic BM18-2 colonization through H. Pennisetum grass will aid in the application and maintenance of these bacteria in farming, and it presents new opportunities for the development of innovative strategies in the fields of agriculture and biotechnology.