LAUSR

Plant genetic transformation systems have facilitated insights into molecular plant biology and revolutionized commercial agriculture. Unfortunately, agrobacterium-mediated transformation was still the main method although its subsequent regeneration process from tissue culture in cotton remained arduous even after 30 years of technological advances. At the same time, a number of transformation methods based on pollen grains have been developed, such as electroporation, biolistic bombardment, ultra-sonication, and Agrobacterium incubation in plant pollens. But these pollen-based techniques have not been widely adopted. In this chapter, we have presented a protocol of pollen-based transformation technology in cotton, "pollen magnetofection," to directly produce transgenic seeds without tissue culturing. In this system, magnetic nanoparticles loaded with pure plasmid DNA carrying functional genes were delivered into pollens via pollen apertures in the presence of a magnetic field. Afterward, these magnetofected pollens were used for pollination, to produce transformed seeds. Pollen magnetofection is a genotype-independent transformation system; in addition, exogenous DNA was successfully integrated into the genome and stably expressed in the successive generations. We emphasize that pollen magnetofection is a most efficient platform for genetic transformation of cotton and other crops with high-throughput and efficient potential infield operation.