Drought stress affects cereals especially during the reproductive stage. Researchers at Virginia Tech University studied the maize (Zea mays) drought transcriptome using RNA-Seq analysis to compare drought treated and well-watered fertilized ovary and basal leaf meristem tissue.
More drought responsive genes responded in the ovary compared to the leaf meristem. Gene Ontology (GO) enrichment analysis revealed massive decrease in transcript abundance of cell division and cell cycle genes in the drought stressed ovary only.
The data are discussed in the context of the susceptibility of maize kernel to drought stress leading to embryo abortion, and the relative robustness of dividing vegetative tissue taken at the same time from the same plant subjected to the same conditions. The scientists working hypothesis involves signaling events associated with increased ABA levels, decreased glucose levels, disruption of ABA/sugar signaling, activation of PCD/senescence through repression of a PLC-mediated signaling pathway, and arrest of the cell cycle in the stressed ovary at 1DAP. Increased invertase levels in the stressed leaf meristem, on the other hand, resulted in that tissue maintaining hexose levels at an “unstressed” level, and at lower ABA levels, which was correlated with successful resistance to drought stress.
- Kakumanu A, Ambavaram MM, Klumas CM, Krishnan A, Batlang U, Myers E, Grene R, Pereira A. (2012) Effects of Drought on Gene Expression in Maize Reproductive and Leaf Meristem Tissue Revealed by RNA-Seq. Plant Physiol [Epub ahead of print]. [article]