Weighted Gene Coexpression Network Analysis-Based Identification of Key Modules and Hub Genes that Regulate the Drought Stress Response in the Rice Drought-Sensitive Line PY6

Abstract

Drought stress is an adverse factor with deleterious effects on several aspects of rice growth. However, the mechanism underlying drought resistance in rice remains unclear. To understand the molecular mechanism of the drought response in rice, drought-sensitive CSSL (Chromosome Single-substitution Segment Line) PY6 was used to map QTLs of sensitive phenotypes and to reveal the impact of the QTLs on transcriptional profiling. The dss-1 locus was mapped onto the short arm of chromosome 1 of rice. According to transcriptomic analysis, the identified differentially expressed genes (DEGs) exhibited a downregulated pattern and were mainly enriched in photosynthesis-related GO terms, indicating that photosynthesis was greatly inhibited under drought. Further, according to weighted gene coexpression network analysis (WGCNA), 4 and 3 modules were strongly correlated with H2O2 and MDA, respectively. Likewise, GO analysis revealed that the photosynthesis-related GO terms were consistently overrepresented in H2O2-correlated modules. Functional annotation of the DEGs in the H2O2 and MDA-correlated modules revealed cross-talk between abiotic and biotic stress responses for these genes, which were annotated as encoding WRKYs and PR family proteins, were notably differentially expressed between PY6 and PR403.We speculated that drought-induced photosynthetic inhibition leads to H2O2 and MDA accumulation, which can then trigger the reprogramming of the rice transcriptome, including the hub genes involved in ROS scavenging, to prevent oxidative stress damage. Our results shed light on and provide deep insight into the drought resistance mechanism in rice.

Genes and pathways associated with drought tolerance in Populus wutunensis under drought stress

“…The aggravation of drought may lead to the death of trees in larger areas [3], and serious economic losses to agricultural and forestry production [4]. Many regions of the world are facing immense pressure to improve crop production e ciency by reducing water use [5], and more research is being dedicated to understanding the drought resistance mechanism of crops and increasing drought resistance [6,7]. Plants mainly deal with drought through drought escape, drought avoidance, and drought resistance [8].…”