Comparative profiling of volatile organic compounds associated to temperature sensitive resistance to wheat streak mosaic virus (WSMV) in resistant and susceptible wheat cultivars at normal and elevated temperatures

Comparative metabolites analysis of resistant, susceptible and wild rice species in response to bacterial blight disease

Globally, rice bacterial blight disease causes significant yield losses. Metabolomics is a vital tool for understanding this disease by analyzing metabolite levels and pathways involved in resistance and susceptibility. It enables the development of disease-resistant rice varieties and sustainable disease management strategies. This study has focused on the metabolic response to bacterial blight disease in three rice varieties: the near isogenic rice line IRBB27, wild rice (Oryza minuta-CG154:IRGC No. 93259, accession No. EC861737), and the susceptible control IR24. However, detailed metabolomics studies in wild rice remain largely unexplored. So, metabolic analysis with untargeted liquid chromatography mass spectrometry analysis (LC-MS/MS) was performed at various time points, including pre infection and post infection at 12 h and 24 h with Xanthomonas oryzae pv. oryzae (Xoo). In this study, a total of 6067 metabolites were identified. Pre-infection stage of the susceptible, resistant, and wild rice had 675, 660, and 702 identified metabolites, respectively, but these numbers were altered at post-infection stages. Various defense-related metabolites, including amino acids, flavonoids, alkaloids, terpenoids, nucleotide derivatives, organic acids, inorganic compounds, fatty acid and lipid derivatives have been identified. PCA and PLS-DA plots revealed differences in the metabolome among susceptible, resistant, and wild genotypes, suggesting distinct metabolic profiles for each. In this study, we found 149 metabolites were upregulated and 162 downregulated in the wild type (CG154) compared to the susceptible cultivar (IR24). Similarly, 85 metabolites were upregulated and 92 downregulated in the resistant near isogenic line (IRBB27) compared to IR24, while 156 were upregulated and 149 downregulated in CG154 compared to IRBB27. Key metabolites, including flavonoids, terpenoids, and phenolic compounds, showed significantly higher levels (P ≤ 0.01) in resistant varieties. These identified defense metabolites could serve as potential biomarkers for bacterial blight resistance in rice. The findings from this study have important implications for the development of new rice cultivars with tolerance to bacterial blight disease.

Heat Stress and Plant-Biotic Interactions: Advances and Perspectives

Climate change presents numerous challenges for agriculture, including frequent events of plant abiotic stresses such as elevated temperatures that lead to heat stress (HS). As the primary driving factor of climate change, HS threatens global food security and biodiversity. In recent years, HS events have negatively impacted plant physiology, reducing plant's ability to maintain disease resistance and resulting in lower crop yields. Plants must adapt their priorities toward defense mechanisms to tolerate stress in challenging environments. Furthermore, selective breeding and long-term domestication for higher yields have made crop varieties vulnerable to multiple stressors, making them more susceptible to frequent HS events. Studies on climate change predict that concurrent HS and biotic stresses will become more frequent and severe in the future, potentially occurring simultaneously or sequentially. While most studies have focused on singular stress effects on plant systems to examine how plants respond to specific stresses, the simultaneous occurrence of HS and biotic stresses pose a growing threat to agricultural productivity. Few studies have explored the interactions between HS and plant-biotic interactions. Here, we aim to shed light on the physiological and molecular effects of HS and biotic factor interactions (bacteria, fungi, oomycetes, nematodes, insect pests, pollinators, weedy species, and parasitic plants), as well as their combined impact on crop growth and yields. We also examine recent advances in designing and developing various strategies to address multi-stress scenarios related to HS and biotic factors.

Decoding Metabolic Reprogramming in Plants under Pathogen Attacks, a Comprehensive Review of Emerging Metabolomics Technologies to Maximize Their Applications

In their environment, plants interact with a multitude of living organisms and have to cope with a large variety of aggressions of biotic or abiotic origin. What has been known for several decades is that the extraordinary variety of chemical compounds the plants are capable of synthesizing may be estimated in the range of hundreds of thousands, but only a fraction has been fully characterized to be implicated in defense responses. Despite the vast importance of these metabolites for plants and also for human health, our knowledge about their biosynthetic pathways and functions is still fragmentary. Recent progress has been made particularly for the phenylpropanoids and oxylipids metabolism, which is more emphasized in this review. With an increasing interest in monitoring plant metabolic reprogramming, the development of advanced analysis methods should now follow. This review capitalizes on the advanced technologies used in metabolome mapping in planta, including different metabolomics approaches, imaging, flux analysis, and interpretation using bioinformatics tools. Advantages and limitations with regards to the application of each technique towards monitoring which metabolite class or type are highlighted, with special emphasis on the necessary future developments to better mirror such intricate metabolic interactions in planta.