Biradar Hanamareddy, Karan Ratna, Subudhi Prasanta K
School of Plant, Environmental, and Soil Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, United States.
Department of Agronomy, University of Florida, Gainesville, FL, United States.
Front Plant Sci. 2018 Sep 12;9:1304. doi: 10.3389/fpls.2018.01304. eCollection 2018.
The transgenic technology using a single gene has been widely used for crop improvement. But the transgenic pyramiding of multiple genes, a promising alternative especially for enhancing complexly inherited abiotic stress tolerance, has received little attention. Here, we developed and evaluated transgenic rice lines with a single Salt Responsive Protein 3-1 () gene as well as pyramids with two-genes and Vacuolar H-ATPase subunit c1 () derived from a halophyte grass L. for salt tolerance at seedling, vegetative, and reproductive stages. The overexpression of this novel gene resulted in significantly better growth of with the recombinant plasmid under 600 mM NaCl stress condition compared with the control. During early seedling and vegetative stages, the single gene and pyramided transgenic rice plants showed enhanced tolerance to salt stress with minimal wilting and drying symptoms, improved shoot and root growth, and significantly higher chlorophyll content, relative water content, and K/Na ratio than the control plants. The salt stress screening during reproductive stage revealed that the transgenic plants with single gene and pyramids had better grain filling, whereas the pyramided plants showed significantly higher grain yield and higher grain weight compared to control plants. Our study demonstrated transgenic pyramiding as a viable approach to achieve higher level of salt tolerance in crop plants.
利用单个基因的转基因技术已被广泛用于作物改良。但是，多个基因的转基因聚合，尤其是对于增强复杂遗传的非生物胁迫耐受性而言是一种有前景的替代方法，却很少受到关注。在此，我们开发并评估了具有单个盐响应蛋白3-1（）基因的转基因水稻品系，以及源自盐生草的具有两个基因和液泡H-ATP酶亚基c1（）的基因聚合体在幼苗期、营养生长期和生殖期的耐盐性。与对照相比，在600 mM NaCl胁迫条件下，该新基因的过表达使得携带重组质粒的生长明显更好。在幼苗早期和营养生长期，单基因和基因聚合的转基因水稻植株对盐胁迫的耐受性增强，萎蔫和干枯症状最小，地上部和根系生长改善，叶绿素含量、相对含水量和K/Na比显著高于对照植株。生殖期的盐胁迫筛选表明，单基因和基因聚合的转基因植株具有更好的籽粒充实度，而基因聚合植株与对照植株相比，籽粒产量显著更高，粒重也更高。我们的研究证明，转基因聚合是在作物中实现更高水平耐盐性的可行方法。
