Biotechnological Advancements and Begomovirus Management in Okra (Abelmoschus esculentus L.): Status and Perspectives

Abstract

Despite the importance of okra, as one of the important vegetable crop, very little attention has been paid to its genetic improvement using advanced biotechnological tools. The exploitation of marker assisted breeding in okra is often limited due to the availability of a few molecular markers, the absence of molecular genetic-map(s), and other molecular tools. Chromosome linkage-groups were not yet constructed for this crop and reports on marker development are very scanty and mostly hovering around cultivar characterization. Besides, very little progress has been observed for transgenic development. However, high throughput biotechnological tools like chromosome engineering, RNA interference (RNAi), marker-assisted recurrent selection (MARS), genome-wide selection (GWS), targeted gene replacement, next generation sequencing (NGS), and nanobiotechnology can provide a rapid way for okra improvement. Further, the etiology of many deadly viral diseases like the yellow vein mosaic virus (YVMV) and okra enation leaf curl virus (OELCV) in okra is broadly indistinct and has been shown to be caused by various begomovirus species. These diseases cause systemic infections and have a very effective mode of transmission; thus, preventing their spread has been very complicated. Biotechnological interventions have the potential to enhance okra production even under different viral-stress conditions. In this background, this review deals with the biotechnological advancements in okra per se along with the begomoviruses infecting okra, and special emphasis has been laid on the exploitation of advanced genomic tools for the development of resistant varieties.

Transcriptome sequencing of okra (Abelmoschus esculentus L. Moench) uncovers differently expressed genes responding to drought stress

“…India is the largest okraplanted country, with an area of over 0.5 million ha, followed by Nigeria and Sudan, which produce 6.3 million MT per year (Varmudy 2011; Faostat 2014). Extensive previous research has mostly focused on cropping systems (Anonymous 2015), nutritional components (Calisir et al 2005), heredity and breeding (Kumar et al 2017;Mishra et al 2017), fresh maintenance (Tajiri 2011) and processing technology (Rai and Balasubramanian 2009). However, reports on the molecular mechanisms of okra are relatively few.…”

Transgenic Breeding Approaches for Improving Abiotic Stress Tolerance: Recent Progress and Future Perspectives

“…Plant biotechnological approaches, such as molecular breeding and genetic engineering, offer the possibility to obtain improved and genome edited crops in a short time [3,10]. Genetic engineering may also allow us to overcome the reproductive barrier among different plant species [10].…”

“…Scientists investigated the gene expression that was potentially involved in plant defense signaling pathways that encoded proteins conferring abiotic stress tolerance. The current efforts to improve plant stress tolerance through genetic transformation have resulted in several important achievements [10]; however, the genetically complex mechanisms of abiotic stress tolerance make the task extremely difficult [3]. Therefore, plant biotechnology should be fully combined with conventional breeding and physiology.…”

“…The intensive increase in biotic and other environmental stresses (high and low temperature, salinity, drought, and heavy metal stresses) due to climate changes can pose a severe threat to tropical crop production [2]. Although conventional breeding techniques have significantly improved crop production and yields, new methodologies and techniques are needed for crop production improvement to fulfill the food demand [3]. Additionally, environmental stresses are defined as the adverse effects of non-living factors on living organisms (plants) in a specific environment.…”

“…To improve plant survival and production efficiency, different approaches have been established to improve plant resistance [3,5]. The exposure of plants to these environmental stresses leads to leads to reactive oxygen species (ROS) overproduction, which negatively affects the activities of enzymes, the biosynthesis of carbohydrates, DNA, proteins, and other biochemical activities, thus leading to oxidative stress ( Figure 1) [6,7].…”