Transformation in Gossypium hirsutum cv. HS6: A Path to Efficient Phytohormonefree Protocol Overcoming Transformation Hurdle

By : Masnad Khan , Divya Sharma , Hussain Ara , Jawaid A. Khan

Page No: 227-234

Abstract
Cotton (Gossypium spp.) is a powerhouse of the textile industry, playing a crucial role in global fibre production. Unfortunately, cotton is not the easiest crop to genetically modify, it is highly recalcitrant with respect to transformation and regeneration. Despite progress in transformation protocols, it’s efficiency in many elite cotton varieties still remains around 0.01-3%. Certain cotton genotypes, such as coker, show more favourable responses to gene transfer, resulting in a dependence on these varieties for genetic alterations. A reliable and efficient protocol for transforming cotton was standardized in Gossypium hirsutum cv HS6. Shoot tip explants from in-vitro germinated cotton seedlings were cultured on MS medium. These explants were genetically transformed with Agrobacterium tumefaciens strain LBA4404, carrying pBI121 expression vector containing neomycin phosphotransferase (nptII) marker gene. The explants were consistently transferred every week to fresh MS selection media. Remarkably, unlike previous protocols that utilized various phytohormones for cotton regeneration, our procedure does not involve use of any phytohormones, yet the growth of shoots and roots was not affected by the absence of phytohormones. Interestingly, natural hormones within cotton plants regulate growth, eliminating the need for external phytohormones in the medium during tissue culture. The overall transformation efficiency reported in the current protocol was 5%, which is significantly higher than previous reports.

Authors:
Masnad Khan, Divya Sharma, Hussain Ara and Jawaid A. Khan
Plant Virus Laboratory, Department of Biosciences, Jamia Millia Islamia, New Delhi, India.
 

DOI: https://doi.org/10.32381/JPSR.2024.40.02.3