A Saline Duper Wheat that Tolerates Higher Salt Concentrations!

Posted by Ilsa Miller on June 30th, 2022

In the past few decades, agricultural land has been largely lost, and increased salinity in soils around the world has received much attention. Nowadays, nearly 8% of the world's arable land can no longer be used for crop cultivation due to salt pollution, and more than half of the world's countries are affected. Wheat is the second largest grain grown after corn and grows more on Earth than any other crop. Therefore, there is a need to increase wheat production to meet the needs of the growing world population. Therefore, the possibility of planting wheat on salinity-affected soils is essential to feed the population and avoid economic losses in the countries involved. In Egypt, Kenya, and Argentina, wheat cannot be grown in large areas, and even low-lying areas in Europe such as the Netherlands, have these problems. Even in Asian regions where rice is currently the main crop, salt-tolerant wheat will become an important component of future food supply, as wheat cultivation requires much less water than rice.

In the present study, a mutagenized population with point mutations was created using the moderately salt-tolerant Bangladeshi wheat cultivar BARI Gom-25 as a source and this cultivar was used as a control for the variant lines. The benefit of point mutations is that populations with high genetic variation can be created. New salt-tolerant varieties can be developed from such populations, as well as many other valuable properties. Seventy mutant lines with higher germination rates than the BARI Gom-25 control were identified by screening the germination rates of approximately 2000 mutant lines on saline filter paper (200 mM NaCl). Further testing was conducted in the field in Bangladesh. Thirty-five of these lines were also analyzed in the Australian Plant Phenomics Facility. In these experiments, yield, growth, ion content, and water consumption were determined, and the search for transcription factor genes related to salt tolerance in the wheat genome was conducted with bioinformatics tools. The focus is on two distinct families of transcription factors; WRKY and MYB. These studies illustrate the importance of bioregulation of salt tolerance and deepen the understanding behind the mechanisms involved. Furthermore, it highlights putative target genes regulated by WRKY and MYB transcription factors. This paper points out the importance of salt-tolerant crops, especially wheat, and shows how mutation breeding can be a method to develop salt-tolerant varieties. Identified specific mutagenized wheat lines with strong salt tolerance based on their performance on various parameters and showed the importance of WRKY and MYB transcription factor families in the biological regulation of salt tolerance. Finally, downstream candidate genes encoding observed phenotypes were analyzed.

The earth's population is growing, and by 2050, 100 million people will need to eat on earth. At the same time, climate change causes arable land on Earth to dry up and other areas to be inundated by rising sea levels. All this has increased interest in salt-tolerant crops. It is very important to develop a salt-tolerant variety with high yield. At present, we lose about 2000 hectares of land per day due to sea level rise and improper irrigation methods that increase soil salinization. "

Johanna Lethin, a doctoral student in the Department of Biological and Environmental Sciences at the University of Gothenburg, said: "The average weight of seeds in the wheat varieties we bred was three times higher than that of the original Bangladeshi wheat, and the germination frequency was also higher." Through DNA analysis and other studies, the team was also able to identify genes that control salt tolerance in wheat plants. This is a milestone in our study. Now we know some genes related to salt tolerance. The next step is to test whether these genes are also present in the best wheat varieties we have mutated."

The new wheat varieties can tolerate the soil with salt concentration, and the seeds are three times heavier and the germination frequency is almost twice that of the original varieties. Although some experiments need to be done, the potential of this finding is global. "The next step is to grow salt-tolerant varieties on the land of Bangladesh. I estimate that it will take about 5 years before we can achieve commercial production of salt-tolerant wheat, depending on the progress of the field experiment."

This study did not use transgenic approaches that are sometimes criticized. In genetically modified crops, the genes of one plant (such as an antifungal plant) are implanted into another plant (such as wheat), so that farmers can avoid using excessive pesticides. In this study, the researchers used a chemical to make point mutations in seeds. In this way, there are no exogenous genes in plants and all mutations may occur naturally.

Collected by Lifeasible, that provides competitive short-turn-around plant breeding services in a wide range of plant species, including major food crops, economic plants, and bio-energy feedstock plants.