Biology subjects

Mbinda, W.

Publications and source records attributed to Mbinda, W..

2 recordsLinked to original sources

bioRxiv2019

Physiological and Biochemical Analyses of Sorghum Varieties Reveal Differential Responses to Salinity Stress

Salinity is among the most severe and widespread environmental constrains to global crop production, especially in arid and semi-arid climates and negatively affecting productivity of salt sensitive crop species. Breeding and selection of salt tolerant crop varieties is therefore necessary for sustainable plant productivity. Given that germination and seeding phases are the most critical phase in the plant life cycle, this study aimed to evaluate seed germination potential and associated traits under salt stress conditions as a simple approach to identify salt tolerant Sorghum varieties. There Sorghum varieties whose adaptation to various agroclimatic conditions is not well elucidated. Salinity stress was applied by addition of NaCl at three different levels of stress (100, 200 and 300 mM NaCl), while plants irrigated with water were used as controls. Evaluation of tolerance was performed on the basis of germination percentage, shoot and seed water absorbance, shoot and root length, leave water content, seedling total chlorophyll content and morphologic abnormality. Our results showed that salinity stress significantly impacts all features associated with germination and early development of seedlings. Our results indicated that that salinity stress substantially affects all traits associated with germination and early seedling growth, with the effect of salinity being dependent on the variety used and level of salinity stress applied. Among the tested Sorghum varieties, Gadam was established to the most salt tolerant variety, suggesting its potential use for cultivation under salinity stress conditions as well as its suitability for use as germplasm material in future Sorghum breeding programmes. For a greater insight into comprehensive mechanisms of salinity tolerance in Sorghum, we suggest further research on genomic and molecular analysis.

plant biology↗

bioRxiv2019

Induced expression of Xerophyta viscosa XvSap1 gene greatly impacts tolerance to drought stress in transgenic sweetpotato

Key message Drought stress in sweetpotato could be overcome by introducing XvSap1 gene from Xerophyta viscosa.\n\nDrought stress often leads to reduced yields and is perilous delimiter for expanded cultivation and increased productivity of sweetpotato. Cell wall stabilization proteins have been identified to play a pivotal role in mechanical stabilization during desiccation stress mitigation. They are involved in myriad cellular processes that modify the cell wall properties to tolerate the mechanical stress during dehydration in plants. This provides a possible approach to engineer crops for enhanced stable yields under adverse climatic conditions. In this study, we introduced the XvSap1 gene isolated from Xerophyta viscosa, a resurrection plant into sweetpotato by Agrobacterium-mediated transformation. Detection of the transgene by PCR coupled with Southern blot revealed the integration of XvSap1 in the three independent events. Sweetpotato plants expressing the XvSap1 gene exhibited superior growth performance such as shoot length, number of leaves and yield than the wild type plants under drought stress. Quantitative real time-PCR results confirmed higher expression of the XvSap1 gene in XSP1 transgenic plants imposed with drought stress. In addition, the transgenic plants had increased levels of chlorophyll, free proline and relative water content but malonaldehyde content was decreased under drought stress compared to wild type plants. Conjointly, our findings show that XvSap1 can enhance drought resilience without causing deleterious phenotypic and yield changes, thus providing a promising candidate target for improving the drought tolerance of sweetpotato cultivars through genetic engineering. The transgenic drought tolerant sweetpotato line provides a valuable resource as drought tolerant crop on arid lands of the world.

molecular biology↗