The SHORT INTERNODES (SHI)-related sequences (SRS) are plant-specific transcription factors that have been quantitatively characterized during plant growth, regeneration, and stress responses. However, the genome-wide discovery of SRS family genes and their involvement in abiotic stress-related activities in cassava have not been documented. A genome-wide search strategy was used to identify eight family members of the SRS gene family in cassava (Manihot esculenta Crantz). Based on their evolutionary linkages, all MeSRS genes featured homologous RING-like zinc finger and IXGH domains. Genetic architecture and conserved motif analysis validated the categorization of MeSRS genes into four groups. Eight pairs of segmental duplications were detected, resulting in an increase in the number of MeSRS genes. Orthologous studies of SRS genes among cassava and three different plant species (Arabidopsis thaliana, Oryza sativa, and Populus trichocarpa) provided important insights into the probable history of the MeSRS gene family. The functionality of MeSRS genes was elucidated through the prediction of protein–protein interaction networks and cis-acting domains. RNA-seq data demonstrated tissue/organ expression selectivity and preference of the MeSRS genes. Furthermore, qRT-PCR investigation of MeSRS gene expression after exposure to salicylic acid (SA) and methyl jasmonate (MeJA) hormone treatments, as well as salt (NaCl) and osmotic (polyethylene glycol, PEG) stresses, showed their stress-responsive patterns. This genome-wide characterization and identification of the evolutionary relationships and expression profiles of the cassava MeSRS family genes will be helpful for further research into this gene family and its function in stress response. It may also assist future agricultural efforts to increase the stress tolerance of cassava.

In recent years, the bacterial blight of cassava has caused substantial economic losses to the Chinese cassava industry. Chemical control methods have become the primary approach to control this disease; however, their widespread usage and harmful residues have raised concerns about environmental pollution. In order to avoid this, it is urgent to seek a green ecological method to prevent and control it. Biological control through the utilization of microorganisms not only effectively inhibits the disease, but also gives consideration to environmental friendliness. Therefore, investigating an endophytic biological control method for cassava bacterial blight is of great importance. In this study, cassava leaf tissues were used as test specimens in order to isolate endophytic bacteria by using dilution and separation methods. Bacillus ME9, derived from cassava endophytic bacteria, exhibits good antagonism against a diverse range of pathogens, including Xpm11. Its genome consists of a series of genes encoding antibacterial lipopeptides, which may be directly related to its antibacterial capabilities. Furthermore, inoculation resulted in a substantial change in the diversity of the endophytic bacterial community, characterized by improved diversity, and displayed an obvious inhibition of pathogenic bacterial growth, demonstrating successful colonization within plants. The results laid a foundation and provided theoretical support for the development and utilization of cassava endophytic bacterial diversity and endogenous disease control strategies.

This study aimed to determine the effects of different dosages of an organic amendment, consisting of a Chinese herbal compound, on cassava growth and rhizosphere microbial diversity. In this study, cassava SC8 growth was determined under four treatments. The growth was promoted with the application of an organic herbal compound amendment, biochar powder, and an agent, in the following groups: 900 kg/ha of organic amendment powder (topdressing) + agent (T1); 1200 kg/ha of organic amendment powder (topdressing) + agent (T2); 1500 kg/ha of organic amendment powder (topdressing) + agent (T3); and an unfertilized control (T4). After 240 days of treatment, the height, the diameter of the stem, the maximum perimeter of the cassava, the tuber number, the weight of a single tuber, the yield per hectare, the mineral elements in the cassava plant, the ash content in the starch and the microbial diversity in the soil were measured. Compared with the control group, the application of 1200 kg of the Chinese herbal compound amendment per ha (T2) had the strongest positive effect on cassava growth, while the height, diameter of the stem and yield per hectare all showed increases of 24.22%, 18.82% and 35.71%, respectively. As for the dry matter content of the tubers, that of T2 decreased by 5.96% compared with T4, while no substantial difference existed among the other groups. The Fe content in T2 decreased by 29.46%, and the Zn in T3 increased by 39.48%, while the contents of other metal ions in the four treatment groups showed no substantial difference. At the same time, the experiment also revealed that, in terms of the bacterial abundance in the soil, Streptophyta dominated in T2, and Fimbriimonas was the unique genera of T2. In addition, the abundances of Nocardioides and unclassfied_Spartobacteria in the T2 group were greatly considerable compared to the other treatment groups. In terms of the fungal abundance in the soil, after being treated with different concentrations, the composition of the soil’s fungi differed greatly among the groups, and the samples at different concentrations contained more than 20 species of unique bacteria. At the genus level, compared with the control group, the relative abundance of unclassfied_Chaetomiaceae in the treatment groups was considerably reduced, and the relative abundance of Psathyrella in T1 increased substantially. The results indicated that the organic amendment could improve the growth of cassava, as well as help to enhance the diversity and optimize the composition of the rhizosphere microbiome.