Genes of Microorganisms: Paving Way to Tailor Next Generation Fungal Disease Resistant Crop Plants

Abstract

The automation of sequencing technologies, flooding in the knowledge of plant-pathogen interactions and advancements in bioinformatics provide tools leading to better knowledge not only of the genome of plant pathogens or microorganism beneficial to plants but also of ways of incorporating genes from microbes into plants as microbial-derived resistance. The identification of various microorganism genes playing key role during pathogensis and the dissection of the signal transduction components of the hypersensitive response and systemic acquired resistance pathways have greatly increased the diversity of options available for tailoring fungus resistant crops. The genetically engineered plants carrying these genes showed spontaneous activation of different defense mechanisms, leading the plant in an elevated state of defense. This 'defense mode' greatly enhances the plant's ability to quickly react to a pathogen invasion and more successfully overcome the infection. The aim of this review is to highlight the dynamic use of genes of microorganisms in enhancing crop tolernace towards fungal intruders by examining the most relevant research in this field.

Biocontrol Potential of Salt-Tolerant Trichoderma and Hypocrea Isolates for the Management of Tomato Root Rot Under Saline Environment

“…It has been observed in several reports that Trichoderma spp. inhibits the growth of various soil-borne pathogens by secreting chitinases (Rai et al 2016a;Almeida et al 2007;Kashyap et al 2011), β-glucanases (Haran et al 1995), and proteinases (Geremia et al 1993) enzymes. Similarly in the current study, Trichoderma and Hypocrea isolates displayed significant biological control activity toward R. solani on both dual plate confrontation as well as volatile metabolite assays; however, a noticeable decline was observed in their antagonistic activity as salt concentration increased.…”

“…The vertical bars indicate the standard error of three replications and different letters on the error bars indicate significant difference (p < 0.05) analyzed by DMRT under saline environment. Several reports indicated that plant growth promotion by these isolates display augmentation of defense-related plant enzymes viz., β-1,3-glucanases, chitinases peroxidases, and phenylalanine peroxidases (Rawat et al 2013;Solanki et al 2011;Harman 2006;Kashyap et al 2011). Alternations in plant metabolism trigger accretion of antimicrobial compounds (such as phytoalexin and phenolics) to offer durable resistance against distinct types of abiotic and biotic stresses (Mohiddin et al 2010;Heydari and Pessarakli 2010;Shoresh et al 2010).…”

The pragmatic introduction and expression of microbial transgenes in plants

“…Plant biotechnologists also showed great interest in protecting vulnerable plant varieties by activating their defense responses (Table 1). While the inhibition of virulence factors is also under intense investigation, avirulence genes (Avr) in plant pathogens and their corresponding resistance genes (receptors) in the host plants have received considerable attention in the past two decades, because the products of resistance genes may directly or indirectly serve as receptors for pathogen Avr factors [33,34]. Plants express resistance by activating appropriate signal transduction pathways, in which elicitors are the primary messengers (product of Avr) that interact with the products of the corresponding genes (receptors), thereby activating plant defense mechanisms.…”

“…Plants express resistance by activating appropriate signal transduction pathways, in which elicitors are the primary messengers (product of Avr) that interact with the products of the corresponding genes (receptors), thereby activating plant defense mechanisms. Elicitors are mostly encoded by pathogens themselves, while in some cases, pathogens hydrolyze the plant cell wall, and the hydrolyzed components work as elicitors or primary messengers in signal transduction [34,35].…”

“…The heterologous expression in plant-based systems is known as plant-molecular farming. In this approach, transgenic plants overexpressing genes for avirulence (avrPto), pectate lyase (PL3), tabtoxin resistance, chloroperoxidase, chitinases, β-1,3 glucanase, and polygalacturans have been shown to exhibit enhanced levels of resistance to bacterial and fungal infections or delayed disease symptoms in response to microbial invasion [34,36].…”