Researchers at the University of Hiroshima are getting closer to uncovering the molecular processes behind how floods deprive plants of oxygen. This will help create more flood-tolerant crops. Phys.org portal.
According to the World Bank, floods are a global risk that threatens the lives and property of billions of people. Even more people are at risk of starvation as a result of floods: water can flood crops. Researchers are now closer to identifying molecular processesunderlying how floods deprive plants of oxygen. This will help create more resilient crops.
With meta-analysis, which involves re-analyzing data from other studies in general, a team from the Graduate School of Integrated Life Sciences at the University of Hiroshima found several common genes and related mechanisms in rice (Oryza sativa) and Arabidopsis (Arabidopsis thaliana). The scientists published their research results in the journal Life.
“Hypoxia is an abiotic stress for plants, often caused by flooding,” said study co-author Keita Tamura, referring to the lack of oxygen caused by oversaturation. “Although a lot of research has been done in the past, we thought that hidden biological mechanisms can be discovered by analyzing multiple studies using meta-analysis of publicly available data.”
The team focused on rice and watercress, as the genetics of both species had previously been extensively studied. According to Tamura, rice is also considered one of the most important crops in the world, serving as the main food product for more than four billion people, according to the Advisory Group for International Agricultural Research, so understanding how to prevent a plant from reacting to hypoxia, is crucial.
The researchers identified 29 pairs of RNA sequencing data for Arabidopsis and 26 pairs for rice in both normal and oxygen deficient conditions from the available datasets. According to Professor Hidemasa Bono, RNA sequencing involves deciphering a subject's genetic blueprint at a given point, which means the data can be used to study which genes caused which changes.
“By analyzing RNA sequencing data, we identified 40 and 19 upregulated and downregulated genes in both species,” Bono said. “Among them, some WRKY transcription factors and cinnamate-4-hydroxylase, whose role in the response to hypoxia remains unknown, were generally upregulated in both Arabidopsis and rice.”
According to Bono, this general upregulation means that these molecular mechanisms become more active when there is a lack of oxygen, indicating their specific mechanistic responsibility for how plants respond.
Bono and Tamura compared their results with a similar meta-analysis of hypoxia in human cells and tissue samples. They found that two of the commonly activated genes in lynx and Arabidopsis were suppressed in their human counterparts.
"Our meta-analysis suggests different molecular mechanisms for hypoxia in plants and animals," Bono said. “The candidate genes identified in this study are expected to shed light on new molecular mechanisms of plant response to hypoxia. Ultimately, we plan to manipulate one of the candidate genes with genome editing technology to create flood-tolerant plants.”