Efficient Agrobacterium tumefaciens-mediated genetic transformation of Aloe vera

Abstract

Abstract Genetic transformation of plants has emerged as a core research tool for functional characterization of genes and cultivar improvement in the field of plant biology. Effectually high transformation efficiency is a prerequisite for accomplishing the stated targets. Aloe vera, a tropical cactus plant in distinction to the family Liliaceae, has seized a long history of secular acceptance as a therapeutic agent and is reasonably the most popular herbal remedy these days. However, the genetic transformation of Aloe vera is relatively low and seldom reported formerly. This study aims to optimize Agrobacterium-mediated transformation in Aloe vera by refining several parameters like explant selection, the extent of explant injury during infection, Agrobacterium concentration, co-cultivation pH, and duration and desiccation of plant tissue to improve the infection efficiency. The results showed that an infection efficiency of about 92% was attained by suspending the Agrobacterium cells at a concentration of OD600: 0.4 in co-cultivation media at pH-5.6 to infect the shoot base of aloe by desiccation followed by 3 days of co-cultivation. Desiccation during infection had proved to enhance T-DNA delivery, whereas a higher extent of explant injury was found to curtail the infection efficiency. Thereupon, GUS Histochemical assay, PCR analysis, and Southern blotting were used to substantiate the authentication of positive transgenic plants and analyze the copy number of the nptII gene in the Aloe vera genome. Transformation efficiency of over 7% was obtained, which is higher than the previous reports. This study bestows an improved Agrobacterium-mediated transformation protocol based on desiccation in Aloe vera, which might help in facilitating various gene expression studies and regulation in the aloe plant, eventually allowing the modification of aloe species in an effective medicinal manner.