The impacts of rice varieties with stacked drought tolerance and insect resistance on soil microbiomes are poorly understood. Hence, the objective of this study was to investigate the effects resulting from the cultivation of the drought-tolerant and insect-resistant rice cultivar, Hanhui3T, on soil physical–chemical properties, and bacterial and fungal community composition. Soil samples of Hanhui3T and conventional rice varieties (Hanhui3 and Zhonghua11) were collected in triplicate at the booting stage, and bacterial and fungal population sizes and community structures were assessed using qPCR and Illumina MiSeq sequencing, respectively. The Bt protein concentration of Hanhui3T was significantly higher than that of Hanhui3 and Zhonghua11, while the pH of Hanhui3T was significantly lower. Bacterial population sizes and community composition were significantly different between Hanhui3T and Hanhui3 (or Zhonghua11), while no similar effects were observed for fungal communities. These differences suggest that the effect of Hanhui3T cultivation on bacterial community composition is stronger than the effect on fungal communities. Moreover, bacterial abundance was positively correlated to soil pH, while bacterial community structure variations were mainly driven by soil pH and Bt protein concentration differences. In conclusion, the abundances and structure of bacterial communities were altered in rhizosphere with Hanhui3T cultivation that changed soil pH and Bt protein concentrations, while fungal communities displayed no such responsiveness.

Summary: Environmental stressors, especially low temperature, are very common on the earth's dryland systems. Terrestrial cyanobacteria have evolved with cold adaptability in addition to extreme dryness and high irradiation resistance. The dryland soil surface‐dwelling species, Nostoc flagelliforme , serves as a potential model organism to gain insights into cyanobacterial cold adaptation. In this study, we performed transcriptomic analysis of N . flagelliforme samples in response to low temperature. The results revealed that the biological processes, such as terpenoid biosynthetic process, oxidoreductase activity, carbohydrate metabolism, biosynthesis of secondary metabolites, lipid and nitrogen metabolism, were significantly and dynamically changed during the cold stress. It was noteworthy that the transcription of the denitrification pathway for ammonia accumulation was enhanced, implying an importance for nitrogen utilization in stress resistance. In addition, characterization of a cold‐responsive hypothetical gene csrnf1 found that it could greatly improve the cold‐resistant performance of cells when it was heterologously expressed in transgenic Nostoc sp. PCC 7120. It was also found that csrnf1 transgenic strain exhibited resistance to nitrogen‐deficient environmental stress. Considering that dryland cyanobacteria have to cope with low temperature on infertile soils, this study would enrich our understanding on the importance of multifunction of the genes for environmental cold adaptation in drylands.