Poster Presentation International Plant Molecular Biology Conference 2024

Functional Mechanism of ZmDRESH8 and ZmSIZ1a-Mediated Small RNA in Regulating Drought Response in Maize (#20)

Xiaopeng Sun 1 , Yanli Xiang 1 , Nannan Dou 1 , Hui Zhang 1 , Mingqiu Dai 1
  1. Huazhong Agricultural University, Wuhan, HUBEI, China

Maize yields have shown a significant increase over the past century; however, this progress has been accompanied by an increased susceptibility to drought. In order to gain deeper insights into the genomic mechanisms underlying environmental adaptation and yield optimization, we conducted a thorough analysis of sRNAome and transcriptome profiles within a diverse global maize panel exposed to various environmental stimuli. By employing advanced bioinformatics techniques, we successfully identified a transposon, TE-IR, which we named ZmDRESH8 (Drought-Related Environment-Specific Super eQTL Hotspot located on chromosome 8). Our discoveries highlight the crucial role of TE-IR-mediated post-transcriptional regulation in maintaining the delicate balance between crop adaptation to environmental stressors and maximizing yield production.Furthermore, utilizing the aforementioned sRNA dataset, we identified a gene closely associated with small RNAs, ZmSIZ1a, which codes for SUMO E3 ligase. Through sRNA sequencing of siz1a genetic material, we observed that ZmSIZ1a predominantly regulates the expression of 24 nt siRNA. Subsequent molecular assays revealed that ZmSIZ1a utilizes SUMOylation to target the small RNA processing RNA polymerase NRPD1. Importantly, our experimental data indicated that the overexpression of SIZ1a resulted in reduced SUMOylation of NRPD1 compared to the wild-type material. These findings collectively indicate that SIZ1a-mediated SUMOylation of NRPD1 promotes its degradation, thereby exerting a negative regulatory effect on the accumulation of 24 nt siRNA.