Abstract Cassava (Manihot esculenta Crantz) is worldwide the sixth-largest food crop and highly drought resistant. The expression of the myeloblastosis (MYB) family protein MeMYB26 in cassava was previously reported to be significantly up-regulated under water deficit. To study the basic characterization, natural variations and potential functions of MeMYB26 for drought resistance in cassava, the protein was subjected to bioinformatics analysis, multiplex-PCR with next-generation sequencing and candidate association studies. The results indicated that MeMYB26 is a typical transcription factor, with two MYB DNA-binding and transcriptional activation domains. One stop-gained and five nonsynonymous variations in the genomic region of MeMYB26 were significantly associated with drought resistance traits. The results of the scale-free coexpression network showed that the MeMYB26 gene plays a critical role in plant stress resistance, growth and biomass development. It was concluded that MeMYB26 is a reliable candidate gene associated with drought tolerance and biomass storage in cassava.

ABSTRACT: The impacts of continuous cropping of banana on soil microbiological and biochemical properties are little understood. In this study, we evaluated the variations in soil bacterial community abundance and diversity, microbial biomass carbon (MBC) and nitrogen (MBN) as well as soil enzyme activities involved in C, N and P cycles as affected by continuous cropping of banana. An initial increase in bacterial 16S rRNA copy and soil microbial biomass was observed in the second cropping and then decreased until the fourth cropping. The diversity of bacterial community showed a continuous decrease throughout the experiment. In addition, continuous cropping of banana caused shifts in bacterial community composition and structures. Soil urease and invertase exhibited the highest activities in the second cropping and then decreased gradually from the second to the fourth cropping. The phosphatase activity showed a gradual increase from the first to the third cropping. The bacterial 16S rRNA copy was positively correlated with the contents of MBN and urease activities. The results indicated that continuous cropping of banana was responsible for the disturbance of the bacterial community and that the effect on enzyme activity varies depending on the type of soil enzyme.

A novel fluorescent probe for Mg²+ based on coumarin Schiff-base was synthesized and characterized. The sensor displayed high selectivity toward Mg²+ in acetonitrile, and shows 1:1 complex formation with Mg²+ in acetonitrile.