Overexpressing the IPT gene improves drought tolerance and nutritional value of tropical maize (Zea mays L.)

Abstract

Drought stress poses a significant threat to crop productivity, making the development of drought-tolerant crops a priority. The impact of drought on grain yield loss varies significantly, ranging from 10% to 76%, depending on the specific stage of occurrence and the severity of the drought. In this study, we investigated the effects of introducing the pSARK::IPT transgene on the drought tolerance and nutritional composition of successive generations of tropical maize. Towards this goal, we screened different generations of maize plants by genotyping PCR, exposed them to long term drought stress and analysed several drought stress markers and nutritional profiles of the plants. Our results demonstrated that the pSARK::IPT transgene was present in 4 successive generations of maize plants. Under drought conditions, transgenic maize exhibited higher relative water content, and delayed senescence compared to wild-type plants. Additionally, transgenic plants showed increased levels of total chlorophyll, chlorophyll a, and chlorophyll b, indicating improved photosynthetic activity under water deficit. Our study also showed that IPT-transgenic plants produced substantially higher yields and demonstrated enhanced nutritional value compared to wildtype plants when grown under well-watered conditions. Further research is warranted to investigate the underlying molecular mechanisms involved in these improvements and assess the performance of pSARK::IPT maize under field conditions.