Use of deep sequencing to profile small RNAs derived from tomato spotted wilt orthotospovirus and hippeastrum chlorotic ringspot orthotospovirus in infected Capsicum annuum

Advances in understanding the interaction between Solanaceae NLR resistance proteins and the viral effector Avr

The rising prevalence of viral-induced diseases, particularly those caused by certain strains, poses a substantial risk to the genetic diversity of Solanaceae crops and the overall safety of horticultural produce. According to the "gene-for-gene" hypothesis, resistance proteins are capable of selectively identifying nontoxic effectors produced by pathogens, as they are under purview of the host's immune defenses. The sensitivity and responsiveness of Solanaceae plants to viral attacks play a crucial role in shaping the outcomes of their interactions with viruses. Pathogenic organisms, devise an array of infection tactics aimed at circumventing or neutralizing the host's immune defenses to facilitate effective invasion. The invasion often accomplishes by suppressing or disrupting the host's defensive mechanisms or immune signals, which are integral to the infection strategies of such invading pathogens. This comprehensive review delves into the myriad approaches that pathogenic viruses employ to infiltrate and overcome the sophisticated immune system of tomatoes. Furthermore, the review explores the possibility of utilizing these viral strategies to bolster the resilience of horticultural crops, presenting a hopeful direction for forthcoming progress in plant health and agricultural stability.

Comprehensive phytohormone metabolomic and transcriptomic analysis of tobacco (Nicotiana tabacum) infected by tomato spotted wilt virus (TSWV)

Tomato spotted wilt virus (TSWV) is ranked among the top 10 most destructive viruses globally. It results in abnormal leaf growth, stunting, and even death, significantly affecting crop yield and quality. Phytohormones play a crucial role in regulating plant-virus interactions. However, there is still limited research on the effect of TSWV on phytohormone levels, particularly growth hormones and genes involved in the phytohormone pathway. In our study, we combined phytohormone metabolomics and transcriptomics to examine the impact of TSWV infection on phytohormone content and gene expression profile. Metabolomic results showed that 41 metabolites, including major phytohormones and their precursors and derivatives were significantly altered after 14 days of TSWV inoculation tobacco plants cvK326, with 31 being significantly increased and 10 significantly reduced. Specifically, the levels of abscisic acid (ABA) and jasmonoyl-isoleucine (JA-Ile) were significantly reduced. The levels of indole-3-acetic acid (IAA) have remained unchanged. However, the levels of cytokinin isopentenyladenine (iP) and salicylic acid (SA) significantly increased. The transcriptome analysis revealed 2,746 genes with significant changes in expression. Out of these, 1,072 genes were significantly downregulated, while 1,674 genes were significantly upregulated. Among them, genes involved in ABA synthesis and signaling pathways, such as 9-cis-epoxycarotenoid dioxygenase (NCED), protein phosphatase 2C (PP2C), serine/threonine-protein kinase (SnRK2), and abscisic acid responsive element binding factor (ABF), exhibited significant downregulation. Additionally, expression of the lipoxygenase gene LOX, Jasmonate ZIM domain-containing protein gene JAZ, and transcription factor gene MYC were significantly down-regulated. In the cytokinin pathway, while there were no significant changes in the expression of the cytokinin synthesis genes, a significant downregulation of transcriptionally active factor type-B response regulators (type-B RRs) was observed. In terms of SA synthesis and signaling pathways, the isochorismate synthase gene ICS1 and the pathogenesis-related gene PR1 were significantly upregulated. These results can strengthen the theoretical foundation for understanding the interaction between TSWV and tobacco and provide new insights for the future prevention and control of TSWV.