Transcriptional Responses of Resistant and Susceptible Wheat Exposed to Wheat Curl Mite

Abstract

(1) Background: The wheat curl mite (Aceria tosichella Keifer) is a key pest of wheat (Triticum aestivum L.) worldwide. While a number of wheat cultivars resistant to the mites have been employed to minimize the impact on the yield and quality of grain, little is known regarding the mechanisms underlying host plant resistance. Therefore, the goal of this study was to explore changes in transcriptome of resistant and susceptible wheat in order to quantify the molecular changes that drive host plant resistance. (2) Methods: Two varieties, wheat curl mite-susceptible (Karl 92) and wheat curl mite-resistant (TAM112) wheat, both at 2-week postemergence, were used in this study. Half of the plants were exposed to wheat curl mite herbivory and half remained mite-free and served as controls. Transcriptome changes were quantified using RNA-seq and compared among treatments to identify genes and pathways affected by herbivores. (3) Results: We identified a number of genes and pathways involved in plant defenses against pathogens, herbivores, and abiotic stress that were differentially expressed in the resistant wheat exposed to wheat curl mite herbivory but were unaffected in the susceptible wheat. (4) Conclusions: Our outcomes indicated that resistant wheat counteracts wheat curl mite exposure through effective induction of genes and pathways that enhance its defense responses.

Transcriptome Sequence Analysis of the Defense Responses of Resistant and Susceptible Cucumber Strains to Podosphaera xanthii

“…In this study, the resistant line had comparatively more DEGs than did the susceptible line under P. xanthii invasion. This finding was similar to those found in previous transcriptomic studies in sorghum, sugarcane and wheat, in which resistant lines induced expression of more DEGs than did susceptible lines under biotic stress ( Kiani and Szczepaniec, 2018 ; De Mello et al, 2020 ; Kiani et al, 2021 ).…”

Wheat transcriptomic responses to extended feeding by wheat curl mites

“…The number of DEGs for each cultivar between WCM-infested and uninfested conditions were higher after 10 dpi compared to short-term (1 dpi) feeding 38 . Our results showed the proportion of upregulated DEGs were higher only in the resistant cultivar.…”

“…Wheat transcriptome responses to short-term feeding (1 dpi) by WCM has been recently reported and provided insights about early defense mechanisms utilized by wheat against WCM 38 . However, WCM has a rapid reproductive rate, with egg-adult developmental times of 7 to 10 days 47 .…”

“…While symptoms on wheat leaves are not strong at 10 dpi, the impact of WCM feeding that leads to curling had been started, thus we investigated the variation of the transcriptomic response between resistant and susceptible wheat varieties after extended feeding (i.e., 10 dpi). In their study, Kiani et al 38 used TAM 112 (WCM-resistant cultivar) and Karl 92 (WCM-susceptible cultivar). TAM 112 has two WCM-resistant genes ( Cmc3 and Cmc4 ), and it is one of the parent lines of Byrd that has one WCM-resistant gene ( Cmc4 ) 33 , 48 .…”

“…While WCM resistance genes have been growing in number, the interactions between wheat’s defense mechanisms and WCM’s response and adaptation to these genes is still largely unknown. Kiani et al 38 have provided the only study so far to identify potential genes and pathways in defense against WCM herbivory. After 24-h post infestation (hpi), TAM112 wheat plants showed modifications in their transcriptomes through the expression of genes involved in jasmonic acid (JA) defense pathways, WKRY transcription factors, antioxidation processes, and pathogen-related responses.…”