Siddanna Savadi

Genetic engineering approaches to enhance oil content in oilseed crops

Oilseed crops play an important role in the agricultural economy. Apart from being an integral component of human diet and industrial applications, they are also gaining importance as replacement to fossil fuels for meeting the energy needs. The last two decades have been marked by several important events in genetic engineering and identification of gene targets for enhancing seed oil content in oilseed crops, and will aid the successful development of new generation high yielding oil crops. Specifically, genetic engineering has shown real breakthrough in enhancing oil content in oilseed rape, camelina, soybean and maize. Moreover, ongoing research efforts to decipher the possibilities of genetic modifications of key regulators of oil accumulation along with physiological and biochemical studies to understand lipid biosynthesis will set a platform to produce transgenic oilseed crops with enhanced oil content. In this review, we briefly describe different genetic engineering approaches explored by different researchers for enhancing oil content. Further, we discuss a few promising and potential approaches and challenges for engineering oil content in oilseed crops.

Molecular regulation of seed development and strategies for engineering seed size in crop plants

Seed, a unit of plant reproduction, is an important source of food, feed, and feedstock. Seed size is a key component of a seed yield trait. Improving seed size has been one of the primary goals of plant breeding since the domestication of crop plants. In the last one and half decade, molecular studies on seed development have gained a great importance in plant research and as a result, a number of molecular regulators of seed size have been identified in the model plant Arabidopsis and some of the crop plants. Seed development is a complex process involving a coordinated growth of maternal and zygotic tissues, which is regulated by the integrated action of transcriptional, epigenetic, hormonal, peptide and sugar signaling regulators. In this review, the role of different transcriptional, epigenetic, hormonal, peptide and sugar signaling regulators in seed development pathways are discussed in detail followed by a brief description of the application of the knowledge gained over the years on molecular regulation of seed development for engineering seed size in crop plants using novel transgenic and recently evolved new breeding strategies such as genome editing.

Isolation and expression analyses of KLUH gene in developing seeds and enhanced seed oil in KLUH overexpressing Brassica juncea transgenics

Abstract Improving oil yield of Indian mustard (Brassica juncea) is exigent as it is a major oilseed crop of Indian subcontinent, which has severe shortage of vegetable oil production in the world. Some of the regulators of seed development have been shown to improve oil yield in Arabidopsis. Arabidopsis KLUH (AtKLUH), a maternal regulator of seed size, has been shown to control seed oil content. In this study, we identified three homologs of AtKLUH in B. juncea, BjKLUH1, BjKLUH2-1 and BjKLUH2-2. We observed that BjKLUH1 differentially expresses in developing seeds in B. juncea accessions with varying seed size and oil content. Further, analyses for seed oil content in B. juncea transgenics carrying AtKLUH demonstrated an increase in seed oil up to 8.3% compared to wild-type plants. The results of this study suggest that KLUH may have a role in seed development and is a good candidate for engineering seed oil accumulation in B. juncea.