Whole-Transcriptome Analysis Reveals Autophagy Is Involved in Early Senescence of zj-es Mutant Rice

Area of Science:

• Plant Biology
• Genetics
• Molecular Biology

Background:

• Early senescence in rice leads to reduced yield and quality.
• Understanding the mechanisms of rice senescence is crucial for crop improvement.

Purpose of the Study:

• To characterize an early-senescence rice mutant (zj-es) and elucidate the molecular mechanisms underlying its phenotype.
• To identify the gene responsible for early senescence in the zj-es mutant.

Main Methods:

• Genetic mapping to identify the ZJ-ES gene.
• Whole-transcriptome RNA sequencing (RNA-seq) to analyze gene expression.
• Weighted Gene Co-expression Network Analysis (WGCNA) and competing endogenous RNA (CeRNA) network analysis.

Main Results:

• The zj-es mutant displays severe early senescence phenotypes, including collapsed chloroplasts and reduced agronomic traits.
• A novel gene, ZJ-ES, was mapped to Chromosome 3 and identified as controlling rice early senescence.
• Transcriptome analysis revealed extensive differential expression of mRNAs, lncRNAs, and miRNAs.
• WGCNA identified a key turquoise module associated with early senescence.
• The CeRNA network analysis indicated lncRNAs regulate mRNAs via miRNAs, primarily in ROS-triggered autophagy pathways.
• Accumulation of reactive oxygen species (ROS), increased autophagosomes, and cell death were observed in zj-es leaves.

Conclusions:

• Reactive oxygen species (ROS)-triggered autophagy induces programmed cell death (PCD) and early senescence in the zj-es rice mutant.
• The ZJ-ES gene plays a critical role in regulating this senescence pathway.