Comparative Metabolomic Profiling of Horse Gram (Macrotyloma uniflorum (Lam.) Verdc.) Genotypes for Horse Gram Yellow Mosaic Virus Resistance

Abstract

Horse gram [Macrotyloma uniflorum Lam. (Verdc.)] is an under-utilized legume grown in India. It is a good source of protein, carbohydrates, dietary fiber, minerals, and vitamins. We screened 252 horse gram germplasm accessions for horse gram yellow mosaic virus resistance using the percent disease index and scaling techniques. The percentage values of highly resistant, moderately resistant, moderately susceptible, susceptible, and highly susceptible were 0.34, 13.89, 38.89, 46.43, and 0.34, respectively. Repetitive trials confirmed the host-plant resistance levels, and yield loss was assessed. The present disease index ranged from 1.2 to 72.0 and 1.2 to 73.0 during the kharif and rabi seasons of 2018, respectively. The maximum percent yield loss was noticed in the HS (75.0 –89.4), while HR possessed the minimum (1.2–2.0). The methanolic leaf extracts of highly resistant and highly susceptible genotypes with essential controls were subjected to gas chromatography–mass spectrometry analysis. Differential accumulation of metabolites was noticed, and a total of 81 metabolites representing 26 functional groups were identified. Both highly resistant and susceptible genotypes harbored eight unique classes, while ten biomolecules were common. The hierarchical cluster analysis indicated a distinct metabolite profile. Fold change in the common metabolites revealed an enhanced accumulation of sugars, alkanes, and carboxylic acids in the highly resistant genotype. The principal component analysis plots explained 93.7% of the variation. The metabolite profile showed a significant accumulation of three anti-viral (octadecanoic acid, diphenyl sulfone, and 2-Aminooxazole), one insecticidal (9,10-Secocholesta-5,7,10(19)-triene-3,24,25-triol), one antifeedant (cucurbitacin B), and six metabolites with unknown biological function in the highly resistant genotype.

Metabolomics‐driven investigation of plant defense response against pest and pathogen attack

“…In the following paragraphs, we are exploring what was done and what is known about the metabolic changes, corresponding to defence signalling, occurring in plants subjected to biotic stressors, such as bacterial, fungal, viral and insect herbivory. To date, metabolomic profiling during pathogen infection has been attempted in Catharanthus roseus (Choi et al 2004, López‐Gresa et al 2017), rice (Sana et al 2010, Hidayah et al 2021, Pretorius et al 2022), Epipactis plant species (Lallemand et al 2019), Arabidopsis (Schlaeppi et al 2010), Alternaria brasicicola (Botanga et al 2012), canola (Ferdausi et al 2023, Adhikary et al 2024), and horse gram (Rajaprakasam et al 2023). Similarly, metabolomics has been performed during pest infestation as well in few plants, namely Zea mays (Wang et al 2022b), Hordeum vulgare (Hamany Djande et al 2022), Chrysanthemum morifolium (Xu et al 2021), Glycine max (Murakami et al, 2014, Yousefi‐Taemeh et al, 2021, Aguiar et al, 2022), maize, sorghum (Kumar and Dhillon 2015), Solanum lycopersicum (Kundu et al 2018), Azadirachta indica (Dawkar et al 2019), pomegranate (Gupta et al 2021) and Lycopersicon esculentum (Khanna et al 2019).…”

“…, and horse gram(Rajaprakasam et al 2023). Similarly, metabolomics hasT A B L E 1 NMR Recognize external characteristics, detect complex structures, sample loss is reduced, require for targeted metabolite Reduced sensitivity, the sample size is large, ineffective for untargeted analysis, inferior resolution (Deborde et al 2017; Emwas et al 2019; Wishart et al 2022; Manickam et al 2023) MS High sensitivity, versatility, expanded coverage An insubstantial amount of ions are studied (Perez de Souza et al 2021; Oh et al 2023)…”

Plant Metabolomics: Current Initiatives and Future Prospects

“…Upon fungal infection, higher quantities of glyceric acid, jasmonic acid, and mucic acid were generated [49]. To better understand the metabolomics of viral infection, horse gram germplasms were evaluated for tolerance to horse gram yellow mosaic virus, marking extreme groups of resistance and susceptibility [50]. GC-MS was used to pinpoint a range of biomolecules that contribute to HgYMV resistance.…”

Carbohydrate Profiling of Different Accessions of Three Underutilized Legumes: A Potential Source of Valuable Nutraceuticals and Pharmaceuticals

“…V. radiata (mung bean) and V. mungo (black gram) are edible underutilized legume crops, grown and consumed by most households in Asia while M. uniflorum (horse gram) is grown for seed and fodder purposes in the arid regions of Asia, Africa, and Australia. [15,16] As an important plant-derived food resource, these legumes are composed of carbohydrates, protein, lipids, crude fiber, and significant amounts of micronutrients. V. radiata starch has been reported to have high AM and RS contents.…”