Intron Retention Fine-Tunes the Resistance of the Rice Mutant pls4 to Rice Sheath Blight(Rhizotonia solani AG I.1a)

OsPLS4 encodes aβ-ketoacyl carrier protein reductase(KAR).The role of OsPLS4 in rice sheath blight(Rhizoctonia solani)remains unclear.Our preliminary studies showed that premature leaf senescence mutants(pls4)were highly susceptive to sheath blight in the early stage of rice development.To explore the role of this gene in the development of rice sheath blight,the transcriptome profiles of the rice pls4 mutant and wild type were compared by RNA-seq.The results revealed 2,569 differentially expressed genes(DEGs).The down-regulated genes were significantly enriched in the defense response-related biological processes.These down-regulated genes included the chitinase genes and WRKY genes,which were significantly changed in pls4 mutants.Furthermore,467 genes induced significant alternative splicing(AS)events.Among them,intron retention(IR)affected gene expression levels and functions of the vitamin B6(VB6)metabolism pathway related to sheath blight.This result suggests that IR plays an important role in the sheath blight resistance of mutant pls4.Together,these results indicate that pls4 could be involved in the biological process of sheath blight via DEGs and the fine-tuning of IR.The present study provides a molecular basis for further investigation of the resistance of rice to sheath blight.

Growth and metal uptake of energy sugarcane (Saccharum spp.) in different metal mine tailings with soil amendments

A pot experiment was conducted to investigate the feasibility of growing energy sugarcane （Sac- charum spp.） in three different metal mine railings （Cu, Sn and Pb/Zn tailings） amended with uncontaminated soil at different mixing ratios. The results indicated that sugarcane was highly tolerant to tailing environments. Amendments of 20% soil to Sn tailings and 30% soil to Cu tailings could increase the biomass of cane-stem for use as the raw material for bioethanol production. Heavy metals were mostly retained in roots, which indicated that sugarcane was useful for the stabilization of the tailings. Bagasse and juice, as the most valuable parts to produce bioethanol, only accounted for 0.6%- 3% and 0.6%-7% of the total metal content. Our study supported the potential use of sugarcane for tailing phytostabilization and bioenergy production.