Towards Improving the Drought Tolerance of Maize Crops by reducing stomatal density

Abstract

Maize supplies adequate energy, carbs, protein, vitamins and minerals, as well as critical nutrients such as iron and potassium for a half of the world’s population. Stomata are small holes on the surface of a plant that control water loss and carbon dioxide uptake. They control global carbon and water cycles with significant regulation. Over the last two decades, carbon dioxide has been increasingly abundant in the Earth’s atmosphere, and it causes problems with germination of plants, a decrease in food security, and starvation. Stronger stomatal development regulation would be an important factor in improving the ability of crops to adapt to current environmental conditions by changing gas exchange. The Epidermal Patterning Factor (EPF) and Epidermal Patterning Factor-Like (EPFL) peptide regulates and influences stomatal density. In relation to stomatal density, EPF1 and EPF2 are regarded as negative regulators while EPFL9 is viewed as a positive regulator. It was decided to modify EPFL9 in Zea mays in order to improve drought tolerance, and some research observed that knocking out EPFL9 reduced stomata. zmEPFL9 has 3 orthologous genes associated with the EPFL9 Arabidopsis thaliana. Statistical analysis carried out via IBM SPSS Statistics of zmEPFL9 showed the SD and SI shows the Arabidopsis transformed of zmEPFL9 chr3 and chr8 were significantly different (P < 0.05) from wild type. But, SD and SI analysis of zmEPFL9 chr4 arabidopsis transformed and wild type arabidopsis shows no difference. This finding reveals that CRISPR Cas9 targeting the genes zmEPFL9 -chr3 or zmEPFL9 -chr8 could improve drought tolerance in maize.