Constitutive H2O2 is involved in sorghum defense against aphids

Abstract

Reactive oxygen species (ROS) play a major role in plant defense against pathogens, but the evidence for their role in defense against insects is still limited. In this study, HN16 and its mutated line (asm1) were used as research objects, and the potential role of H 2 O 2 in sorghum against aphid was examined. Constitutive H 2 O 2 was considered the main factor associated with increased aphid tolerance, although aphid feeding also induced an increase in the H 2 O 2 concentration. By studying ROS scavenging enzymes, it was found that APX and GPX were closely related, but SOD, POX and CAT were not involved in RMES1-mediated resistance. DEGs involved in the detoxification of ROS in HN16 worked through different means. Analysis of three DEGs encoding APX and GPX revealed that although the expression changes of SbAPx1 were consistent and those of SbGPx1 and SbGPx2 were inconsistent with enzyme activity, they all played an important role in RMES1-mediated resistance to aphids.

A Genome-Wide View of Transcriptional Responses during Aphis glycines Infestation in Soybean

“…One of the reactions of plants to insect invasion is generation of ROS [49], and their accumulation contributes to plant's defense against aphids [50][51][52]. However, in our study, although genes related to superoxide metabolism was enriched in GO terms, no significant changes in ROS synthesis were observed in both antixenotic and antibiotic soybean during aphid infestation, but they were increased significantly in the susceptible genotype ( Figure 7).…”

Changes in Aphid—Plant Interactions under Increased Temperature

“…Research on resistant wheat cultivars showed a higher level of CAT than in cultivars susceptible to heat stress [68]. Plant cultivars resistant to phytophagous showed higher CAT activity than sensitive cultivars [69,70].…”

Reactive Oxygen Species in Plant Interactions With Aphids

“…Consistent with this pattern, in a comparison of sorghum genotypes that were resistant or susceptible to the phytotoxic sugarcane aphid (M. sacchari), aphid challenge on resistant plants induced an earlier oxidative response that peaked at 3 days and then declined, whereas H 2 O 2 levels in the susceptible cultivar initially decreased in response to aphids and then increased at 12 days post-infestation, when extensive aphid damage was present (Pant and Huang, 2021). However, heightened H 2 O 2 levels have also been observed in an aphid-resistant chili pepper cultivar 6 days after challenge with avirulent green peach aphids even when aphids were removed 3 days prior (Sun et al, 2020); furthermore, a sorghum genotype resistant to the sugarcane aphid was reported to have constitutively high H 2 O 2 in comparison to a susceptible genotype even in the absence of infestation (Shao et al, 2019). Therefore, certain incompatible interactions also appear to involve long-term ROS accumulation.…”

“…In the S cultivar, H 2 O 2 in infested plants decreased relative to uninfested controls at 3, 6, and 9 days, and increased at 12 days. M. sacchari (Shao et al, 2019)…”

“…However, most studies have measured ROS at a small number of timepoints between 2 and 96 h after infestation (Tables 1, 2). Of the time series conducted within this range, the majority suggest a transient ROS response that peaks on or before 24 h and then declines, often returning to baseline levels 3-4 days after treatment (Moloi and Van Der Westhuizen, 2006;Ren et al, 2014;Sytykiewicz, 2015;Mai et al, 2016Mai et al, , 2017Łukasik et al, 2017;Shao et al, 2019;Woźniak et al, 2019). Certain time series studies, however, did not detect significant increases in ROS until well after 24 h (Kerchev et al, 2012;Yao et al, 2020), or observed ROS levels that peaked after 24 h and/or continued to increase steadily in the days following infestation (Borowiak-Sobkowiak et al, 2016;Sun et al, 2016;Zhang et al, 2019).…”