Determination of the physiological function of a Zea mays pentatricopeptide repeat protein through cultural studies

MSc (Biology), North-West University, Mahikeng CampusFarming of crop plants for food and feed purposes makes agriculture a vital system that sustains both human beings and animals in general. Plants are often affected by various biotic and abiotic stress factors, leading to reduced growth and production. Salinity is one of the major abiotic stresses that severely affects the morphological, biochemical, and physiological processes of plants. Generally, plants naturally display complex interactive and adaptive cellular responses when exposed to salinity or any other stress factor. Therefore, in order to gain a better understanding of the response mechanisms through which plants utilize and survive when exposed to salinity, we targeted the pentatricopeptide repeat (PPR) protein that was previously confirmed as an adenylate cyclase (AC) and known to be involved in various key cell signalling and plant developmental processes under varying environmental stresses. In order to carry this out, wild type (wt) and mutant (mt) maize plant lines for this PPR protein were developed and grown under salt stress, followed by assessment and evaluation of their associated morphological and physiological responses under such conditions, for 16 days. Results obtained indicated that salt stress had severe negative effects on various morphological parameters such as plant height, shoot and root lengths, leaf width, shoot and root weights in mt plant lines than in wt plants. In contrast, increased leaf area in mt plants was observed. In addition, salt stress also affected the physiological parameters such as stomatal density and stomatal count, photosynthesis, respiration, and transpiration in mt plant lines than in wt plants. The study therefore, has successfully managed to determine the physiological and morphological functions of the PPR protein in plants when challenged with salt stress. Thus the protein could be potentially used in breeding and cultivar development programs aimed at developing varieties that are resistant and/or tolerant to salinity.Master