Agrobacterium-mediated Genetic Transformation of Cotton and Regeneration via Somatic Embryogenesis.

Cotton is a significant industrial crop, playing an essential role in the global economy that suffers several setbacks due to biotic and abiotic adversities. Despite such problems, biotechnological advances in cotton are limited because of genetic transformation and regeneration limitations. Here, we present a detailed protocol optimized based on previously published papers, along with our modifications. These involve changes in Agrobacterium concentration, co-cultivation time and temperature, hormones used for regeneration, media manipulation for embryogenic callus production, and efficient rescue of deformed embryos. Further, this protocol has been used in genetic studies on biotic and abiotic stress in cotton. This protocol assures a reproducible stable transgenic cotton development procedure via somatic embryogenesis that can be used by researchers worldwide. This protocol was validated in: Nat Biotechnol (2016), DOI: 10.1038/nbt.3665.

Nitric Oxide Alleviated Arsenic Toxicity by Modulation of Antioxidants and Thiol Metabolism in Rice (Oryza sativa L.).

Nitric oxide (NO) is a gaseous signaling molecule and has a profound impact on plant growth and development. It is reported to serve as pro oxidant as well as antioxidant in plant system. In the present study, we evaluated the protective role of NO against arsenate (As(V)) toxicity in rice plants. As(V) exposure has hampered the plant growth, reduced the chlorophyll content, and enhanced the oxidative stress, while the exogenous NO supplementation has reverted these symptoms. NO supplementation has reduced the arsenic (As) accumulation in root as well as shoot. NO supplementation to As(V) exposed plants has reduced the gene expression level of OsLsi1 and OsLsi2. As(V) stress significantly impacted thiol metabolism, it reduced GSH content and GSH/GSSG ratio, and enhanced the level of PCs. NO supplementation maintained the GSH/GSSG ratio and reduced the level of PCs. NO supplementation reverted As(V) induced iron deficiency in shoot and had significant impact of gene expression level of various iron transporters (OsYSL2, OsFRDL1, OsIRT1, and OsIRO2). Conclusively, exogenous application of NO could be advantageous against As(V) toxicity and could confer the tolerance to As(V) stress in rice.