Background: N⁶-methyladenosine (m⁶A) is the most common RNA modification in eukaryotes and has been implicated as a novel epigenetic marker that is involved in various biological processes. The pattern and functional dissection of m⁶A in the regulation of several major human viral diseases have already been reported. However, the patterns and functions of m⁶A distribution in plant disease bursting remain largely unknown.Results: We analyse the high-quality m⁶A methylomes in rice plants infected with two devastating viruses. We find that the m⁶A methylation is mainly associated with genes that are not actively expressed in virus-infected rice plants. We also detect different m⁶A peak distributions on the same gene, which may contribute to different antiviral modes between rice stripe virus or rice black-stripe dwarf virus infection. Interestingly, we observe increased levels of m⁶A methylation in rice plant response to virus infection. Several antiviral pathway-related genes, such as RNA silencing-, resistance-, and fundamental antiviral phytohormone metabolic-related genes, are also m⁶A methylated. The level of m⁶A methylation is tightly associated with its relative expression levels.Conclusions: We revealed the dynamics of m⁶A modification during the interaction between rice and viruses, which may act as a main regulatory strategy in gene expression. Our investigations highlight the significance of m⁶A modifications in interactions between plant and viruses, especially in regulating the expression of genes involved in key pathways.

Increasing agricultural losses caused by insect infestations are a significant problem, so it is important to generate pest-resistant crop varieties to address this issue. Several reviews have examined aphid–plant interactions from an entomological perspective. However, few have specifically focused on plant resistance mechanisms to aphids and their applications in breeding for aphid resistance. In this review, we first outline the types of resistance to aphids in plants, namely antixenosis, tolerance (cell wall lignification, resistance proteins), and antibiosis, and we discuss strategies based on each of these resistance mechanisms to generate plant varieties with improved resistance. We then outline research on the complex interactions among plants, viruses, and aphids, and discuss how aspects of these interactions can be exploited to improve aphid resistance. A deeper understanding of the epigenetic mechanisms related to induced resistance, i.e., the phenomenon where plants become more resistant to a stress they have encountered previously, may allow for its exploitation in breeding for aphid resistance. Wild relatives of crop plants serve as important sources of resistance traits. Genes related to these traits can be introduced into cultivated crop varieties by breeding or genetic modification, and de novo domestication of wild varieties can be used to exploit multiple excellent characteristics, including aphid resistance. Finally, we discuss the use of molecular design breeding, genomic data, and gene editing to generate new aphid-resistant, high-quality crop varieties.

Rice stripe virus (RSV, genus Tenuivirus, family Phenuiviridae) is the causal agent of rice stripe disease transmitted by the small brown planthopper (SBPH, Laodelphax striatellus) in a persistent propagative manner. The midgut and salivary glands of SBPH are the first and last barriers to the viral circulation and transmission processes, respectively; however, the precise mechanisms used by RSV to cross these organs and transmit to rice plants have not been fully elucidated. We obtained the full-length cDNA sequence of L. striatellus α-tubulin 2 (LsTUB) and found that RSV infection increased the level of LsTUB in vivo. Furthermore, LsTUB was shown to co-localize with RSV nonstructural protein 3 (NS3) in vivo and bound NS3 at positions 74–76 and 80–82 in vitro. Transient gene silencing of LsTUB expression caused a significant reduction in detectable RSV loads and viral NS3 expression levels, but had no effect on NS3 silencing suppressor activity and viral replication in insect cells. However, suppression of LsTUB attenuated viral spread in the bodies of SBPHs and decreased RSV transmission rates to rice plants. Electrical penetration graphs (EPG) showed that LsTUB knockdown by RNAi did not impact SBPH feeding; therefore, the reduction in RSV transmission rates was likely caused by a decrease in viral loads inside the planthopper. These findings suggest that LsTUB mediates the passage of RSV through midgut and salivary glands and leads to successful horizontal transmission. Over 70% of all known plant viruses are transmitted by specific arthropods, mainly including planthoppers, leafhoppers, aphids and whiteflies. Plant viruses with persistent relationships must overcome multiple barriers. Among these barriers, midgut and salivary glands are first and last barriers to the viral transmission. The interactions of host factors and virus in the insect midguts and salivary glands provide critical information regarding viral spread in the insect vector and subsequent infection of host plants. However, the precise mechanisms is still lacking. Here, we found that the specific interaction between a α-tubulin 2 of Laodelphax striatellus (SBPH) (LsTUB) and a nonstructural protein 3 (NS3) Rice stripe virus (RSV) mediates the passage of RSV through midgut and salivary glands, thereby leading to successful horizontal transmission. Our results confirm novel functions of LsTUB and NS3 in RSV transmission in insect vector. LsTUB may be a promising target for blocking horizontal transmission of RSV. These insights provide a better understanding of the interaction between plant viruses and vectors and may develop novel methods to control the systemic spread of plant viruses.