Mungbean plants expressing BjNPR1 exhibit enhanced resistance against the seedling rot pathogen, Rhizoctonia solani

Abstract

Mungbean, Vigna radiata (L.) Wilczek is an important pulse crop that is widely cultivated in semi- arid tropics. The crop is attacked by various soil-borne pathogens like Rhizoctonia solani, which causes dry rot disease and seriously affects its productivity. Earlier we characterized the non-expressor of pathogenesis related gene-1(BjNPR1) of mustard, Brassica juncea, the counterpart of AtNPR1 of Arabidopsis thaliana. Here, we transformed mungbean with BjNPR1 via Agrobacterium tumefaciens. Because of the recalcitrant nature of mungbean, the effect of some factors like Agrobacterium tumefaciens strains (GV2260 and LBA4404), pH, L: -cysteine and tobacco leaf extract was tested in transformation. The transgenic status of 15 plants was confirmed by PCR using primers for nptII. The independent integration of T-DNA in transgenic plants was analyzed by Southern hybridization with an nptII probe and the expression of BjNPR1 was confirmed by RT-PCR. Some of the T(0) plants were selected for detached leaf anti-fungal bioassay using the fungus Rhizoctonia solani, which showed moderate to high level of resistance depending on the level of expression of BjNPR1. The seedling bioassay of transgenic T(2) plants indicated resistance against dry rot disease caused by R. solani.

NPR1 gene transformation as assessed by germ cell in situ transformation pathway into Siraitia grosvenorii

“…4). These observations clearly confirm that NPR1 expression can provide significant protection against tobacco mosaic virus, all of these phenotype have been found to be correlated with the expression of NPR1 (Vilas et al 2010, Vijayan andKirti 2012). Fig.…”

Transgenic Pearl Millet Male Fertility Restorer Line (ICMP451) and Hybrid (ICMH451) Expressing Brassica juncea Nonexpressor of Pathogenesis Related Genes 1 (BjNPR1) Exhibit Resistance to Downy Mildew Disease

“…Similarly, the hybrid ICMH451- BjNPR1 exhibited high level (>91% plants without infection) resistance as compared to isogenic hybrid ICMH451 (>87% infected plants) when challenged with the three virulent strains of S. graminicola (Table 2), suggesting broad spectrum resistance conferred by BjNPR1 gene which can be exploited successfully for the production of commercial hybrids. Earlier, it was reported that transgenic rice and mungbean expressing BjNPR1 , manifested enhanced resistance to Rhizoctonia solani and Magnaporthe grisea pathogens [28], [29]. Similarly, transgenic plants expressing AtNPR1 disclosed resistance to fungal pathogens, such as M. oryzae and Fusarium verticillioides in rice [20], [29], to F. oxysporum , Stemphylium solani and Ralstonia solanacearum in tomato [22], to F. graminearum in wheat [21], to Botrytis cinerea , Alternaria radicina, Sclerotinia sclerotiorum , A. radicin and E. heraclei in carrot [19] and to Verticillium dahliae , F. oxysporum , R. solani , Alternaria alternata and Thielaviopsis basicola in cotton [17], [36].…”

“…Expression of homologues/paralogues of AtNPR1 in rice [24], [25], MpNPR1 in apple [26], Bn NPR1 in Brassica napus [27], BjNPR1 in mung bean [28] and rice [29] also exhibited enhanced resistance to pathogens, suggesting that NPR1-mediated systemic acquired resistance (SAR) mechanism is evolutionarily conserved [23], [30] and hence can be utilized in various crop species for activating SAR.…”

In Planta Genetic Transformation of Mungbean (Vigna radiata (L.) Wilczek) with Marker Gene

“…gus) (Bhajan et al 2019, Yadav et al 2012, Tazeen and Mirza 2004, Jaiwal et al 2001. There are some reports of successful development of transgenic mungbean with alien gene (Baloda and Madanpotra 2017, Kumar et al 2017, Sahoo et al 2016, Vijayan and Kirti 2012, Saini et al 2007 but the success rate is reported to be between 1 and 2%.…”