scholarly journals Comparative transcriptome and histological analyses of wheat in response to phytotoxic aphid Schizaphis graminum and non-phytotoxic aphid Sitobion avenae feeding

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Yong Zhang ◽  
Yu Fu ◽  
Jia Fan ◽  
Qian Li ◽  
Frédéric Francis ◽  
...  
Keyword(s):  
Plant Defence ◽  
Sitobion Avenae ◽  
Schizaphis Graminum ◽  
Wheat Varieties ◽  
Leaf Chlorosis ◽  
Defence Genes ◽  
Genes Encoding ◽  
Defence Responses ◽  
Wheat Leaves ◽  
Ethylene Signalling

Abstract Background Infestation of the phytotoxic aphid Schizaphis graminum can rapidly induce leaf chlorosis in susceptible plants, but this effect is not observed with the nonphytotoxic aphid Sitobion avenae. However, few studies have attempted to identify the different defence responses induced in wheat by S. graminum and S. avenae feeding and the mechanisms underlying the activation of chlorosis by S. graminum feeding. Results S. graminum feeding significantly reduced the chlorophyll content of wheat leaves, and these effects were not observed with S. avenae. A transcriptomic analysis showed that the expression levels of genes involved in the salicylic acid, jasmonic acid and ethylene signalling defence pathways were significantly upregulated by both S. avenae and S. graminum feeding; however, more plant defence genes were activated by S. graminum feeding than S. avenae feeding. The transcript levels of genes encoding cell wall-modifying proteins were significantly increased after S. graminum feeding, but only a few of these genes were induced by S. avenae. Furthermore, various reactive oxygen species-scavenging genes, such as 66 peroxidase (POD) and 8 ascorbate peroxidase (APx) genes, were significantly upregulated after S. graminum feeding, whereas only 15 POD and one APx genes were induced by S. avenae feeding. The activity of four antioxidant enzymes was also significantly upregulated by S. graminum feeding. Cytological examination showed that S. graminum feeding induced substantial hydrogen peroxide (H2O2) accumulation in wheat leaves. The chlorosis symptoms and the loss of chlorophyll observed in wheat leaves after S. graminum feeding were reduced and inhibited by the scavenging of H2O2 by dimethylthiourea, which indicated that H2O2 plays important role in the induction of chlorosis by S. graminum feeding. Conclusions S. graminum and S. avenae feeding induces the JA, SA and ET signalling pathways, but S. graminum activated stronger plant defence responses than S. avenae. S. graminum feeding triggers strong ROS-scavenging activity and massive H2O2 production in wheat leaves, and the accumulation of H2O2 induced by S. graminum feeding is involved in the activation of chlorosis in wheat leaves. These results enhance our understanding of mechanisms underlying aphid-wheat interactions and provide clues for the development of aphid-resistant wheat varieties.

scholarly journals Transcriptome analysis reveals rapid defence responses in wheat induced by phytotoxic aphid Schizaphis graminum feeding

2020 ◽  
Author(s):  
Yong Zhang ◽  
Yu Fu ◽  
Qian Wang ◽  
Xiaobei Liu ◽  
Qian Li ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Schizaphis Graminum ◽  
Feeding Time ◽  
Valuable Insight ◽  
Cereal Aphids ◽  
Expression Levels ◽  
Diphenylene Iodonium ◽  
Defence Responses ◽  
Aphid Feeding ◽  
Wheat Leaves

Abstract Background Schizaphis graminum is one of the most important and devastating cereal aphids worldwide, and its feeding can cause chlorosis and necrosis in wheat. However, little information is available on the wheat defence responses triggered by S. graminum feeding at the molecular level.Results Here, we collected and analysed transcriptome sequencing data from leaf tissues of wheat infested with S. graminum at 2, 6, 12, 24 and 48 hpi (hours post infestation). A total of 125,289 genes were either up- or downregulated and differed significantly in response to aphid feeding. The expression levels of a number of genes (9,761 genes) were significantly altered within 2 hpi and continued to change during the entire 48 h experiment. Gene Ontology analysis showed that the downregulated DEGs were mainly enriched in photosynthesis and light harvesting, and the total chlorophyll content in wheat leaves was also significantly reduced after S. graminum infestation at 24 and 48 hpi. However, a number of related genes of the salicylic acid (SA)-mediated defence signalling pathway and MAPK-WRKY pathway were significantly upregulated at early feeding time points (2 and 6 hpi). In addition, the gene expression and activity of antioxidant enzymes, such as peroxidase and superoxide dismutase, were rapidly increased at 2, 6 and 12 hpi. DAB staining results showed that S. graminum feeding induced hydrogen peroxide (H 2 O 2 ) accumulation at the feeding sites at 2 hpi, and increased H 2 O 2 production was detected with the increases in aphid feeding time. Pretreatment with diphenylene iodonium, an NADPH oxidase inhibitor, repressed the H 2 O 2 accumulation and expression levels of SA-associated defence genes in wheat.Conclusions Our transcriptomic analysis revealed that defence-related pathways and oxidative stress in wheat were rapidly induced within hours after the initiation of aphid feeding. Additionally, NADPH oxidase plays an important role in aphid-induced defence responses and H 2 O 2 accumulation in wheat. These results provide valuable insight into the dynamic transcriptomic responses of wheat leaves to phytotoxic aphid feeding and the molecular mechanisms of aphid-plant interactions.

scholarly journals Deciphering Brassica plant defence responses to cabbage white butterfly egg-associated molecular patterns

2021 ◽  
Author(s):  
Lotte Caarls ◽  
Niccoló Bassetti ◽  
Femke van Doesburg ◽  
Patrick Verbaarschot ◽  
Joop J.A. van Loon ◽  
...  
Keyword(s):  
Plant Defence ◽  
Leaf Tissue ◽  
Molecular Response ◽  
Similar Response ◽  
Callose Deposition ◽  
Brassica Plant ◽  
Defence Genes ◽  
Defence Responses ◽  
Molecular Patterns ◽  
Plant Defence Responses

Brassica plants activate a strong hypersensitive response (HR)-like necrosis underneath eggs of cabbage white butterflies, but their molecular response to eggs is poorly understood. Here, we developed a method to generate egg wash to identify potential insect egg-associated molecular patterns (EAMPs) inducing HR-like necrosis. We found that egg wash, containing compounds from Pieris eggs, induced a similar response as eggs. We show that wash of hatched eggs, of egg glue, and of accessory reproductive glands (ARG) that produce this glue, also induced HR-like necrosis, whereas removal of the glue from eggs resulted in a reduced response. Eggs of Pieris butterflies induced callose deposition, production of reactive oxygen species and cell death in B. nigra and B. rapa leaf tissue, also in plants that did not express HR-like necrosis. Finally, only washes from Pieris eggs induced defence genes and ethylene production, whereas egg wash of a generalist moth did not. Our results indicate that EAMPs are in the egg glue and that the response in B. nigra is specific to Pieris species. Our study expands knowledge on the Brassica-Pieris-egg interaction, and paves the way for identification of EAMPs in Pieris egg glue and corresponding receptor in Brassica spp.

scholarly journals Hunting modulators of plant defence: the grapevine trunk disease fungus Eutypa lata secretes an amplifier for plant basal immunity

2020 ◽  
Vol 71 (12) ◽  
pp. 3710-3724 ◽  
Author(s):  
Pingyin Guan ◽  
Terigele ◽  
Florian Schmidt ◽  
Michael Riemann ◽  
Jochen Fischer ◽  
...  
Keyword(s):  
Plant Defence ◽  
Suspension Cells ◽  
Eutypa Lata ◽  
Grapevine Trunk Diseases ◽  
Molecular Pattern ◽  
Defence Genes ◽  
Trunk Diseases ◽  
Defence Responses ◽  
Basal Immunity ◽  
Actin Remodelling

Abstract Grapevine trunk diseases (GTDs) are progressively affecting vineyard longevity and productivity worldwide. To be able to understand and combat these diseases, we need a different concept of the signals exchanged between the grapevine and fungi than the well-studied pathogen-associated molecular pattern and effector concepts. We screened extracts from fungi associated with GTDs for their association with basal defence responses in suspension cells of grapevine. By activity-guided fractionation of the two selected extracts, O-methylmellein was identified as a candidate modulator of grapevine immunity. O-Methylmellein could not induce immune responses by itself (i.e. does not act as an elicitor), but could amplify some of the defence responses triggered by the bacterial elicitor flg22, such as the induction level of defence genes and actin remodelling. These findings show that Eutypa lata, exemplarily selected as an endophytic fungus linked with GTDs, can secrete compounds that act as amplifiers of basal immunity. Thus, in addition to elicitors that can trigger basal immunity, and effectors that down-modulate antibacterial basal immunity, once it had been activated, E. lata seems to secrete a third type of chemical signal that amplifies basal immunity and may play a role in the context of consortia of mutually competing microorganisms.

scholarly journals Transcriptome analysis reveals rapid defence responses in wheat induced by phytotoxic aphid Schizaphis graminum feeding

2020 ◽  
Author(s):  
Yong Zhang ◽  
Yu Fu ◽  
Qian Wang ◽  
Xiaobei Liu ◽  
Qian Li ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Schizaphis Graminum ◽  
Feeding Time ◽  
Valuable Insight ◽  
Cereal Aphids ◽  
Expression Levels ◽  
Diphenylene Iodonium ◽  
Defence Responses ◽  
Aphid Feeding ◽  
Wheat Leaves

Abstract Background Schizaphis graminum is one of the most important and devastating cereal aphids worldwide, and its feeding can cause chlorosis and necrosis in wheat. However, little information is available on the wheat defence responses triggered by S. graminum feeding at the molecular level. Results Here, we collected and analysed transcriptome sequencing data from leaf tissues of wheat infested with S. graminum at 2, 6, 12, 24 and 48 hpi (hours post infestation). A total of 44,835 genes were either up- or downregulated and differed significantly in response to aphid feeding. The expression levels of a number of genes (9,761 genes) were significantly altered within 2 hpi and continued to change during the entire 48 h experiment. Gene Ontology analysis showed that the downregulated DEGs were mainly enriched in photosynthesis and light harvesting, and the total chlorophyll content in wheat leaves was also significantly reduced after S. graminum infestation at 24 and 48 hpi. However, a number of related genes of the salicylic acid (SA)-mediated defence signalling pathway and MAPK-WRKY pathway were significantly upregulated at early feeding time points (2 and 6 hpi). In addition, the gene expression and activity of antioxidant enzymes, such as peroxidase and superoxide dismutase, were rapidly increased at 2, 6 and 12 hpi. DAB staining results showed that S. graminum feeding induced hydrogen peroxide (H 2 O 2 ) accumulation at the feeding sites at 2 hpi, and increased H 2 O 2 production was detected with the increases in aphid feeding time. Pretreatment with diphenylene iodonium, an NADPH oxidase inhibitor, repressed the H 2 O 2 accumulation and expression levels of SA-associated defence genes in wheat. Conclusions Our transcriptomic analysis revealed that defence-related pathways and oxidative stress in wheat were rapidly induced within hours after the initiation of aphid feeding. Additionally, NADPH oxidase plays an important role in aphid-induced defence responses and H 2 O 2 accumulation in wheat. These results provide valuable insight into the dynamic transcriptomic responses of wheat leaves to phytotoxic aphid feeding and the molecular mechanisms of aphid-plant interactions.

scholarly journals Impacts of Constitutive and Induced Benzoxazinoids Levels on Wheat Resistance to the Grain Aphid (Sitobion avenae)

Metabolites ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 783
Author(s):  
Zhanfeng Zhang ◽  
Hao Lan ◽  
Hehe Cao ◽  
Xiangshun Hu ◽  
Yongliang Fan ◽  
...  
Keyword(s):  
Wheat Breeding ◽  
Sitobion Avenae ◽  
Aphid Resistance ◽  
Dependent Manner ◽  
Callose Deposition ◽  
Wheat Varieties ◽  
Grain Aphid ◽  
Wide Range ◽  
Wheat Leaves ◽  
The Relationship

Benzoxazinoids are important secondary metabolites in gramineae plants and have inhibitory and toxic effects against a wide range of herbivore pests. However, the relationship between benzoxazinoid level and plant resistance to aphids remains controversial. In this study, we investigated the relationship between benzoxazinoids composition and concentration in wheat leaves and the resistance to the grain aphid Sitobion avenae. Overall, six benzoxazinoids were detected and identified by mass spectrometry based metabolites profiling, including three lactams, two hydroxamic acids, and one methyl derivative. The constitutive levels of these benzoxazinoids were significantly different among the wheat varieties/lines. However, none of these benzoxazinoids exhibited considerable correlation with aphid resistance. S. avenae feeding elevated the level of 2-O-β-D-glucopyranosyl-oxy-4,7-dimethoxy-(2H)-1,4-benzoxazin-3(4H)-one (HDMBOA-Glc) and reduced the level of 2-O-β-D-glucopyranosyloxy-4-hydroxy-7-(2H)-methoxy-1,4-benzoxazin-3(4H)-one (DIMBOA-Glc) in some of the wheat varieties/lines. Moreover, aphid-induced level of DIMBOA-Glc was positively related with callose deposition, which was closely associated with aphid resistance. Wheat leaves infiltrated with DIMBOA-Glc caused a noticeable increase of callose deposition and the effect was in a dose dependent manner. This study suggests that the constitutive level of benzoxazinoids has limited impact on S. avenae. Aphid feeding can affect the balance of benzoxazinoids metabolism and the dynamic level of benzoxazinoids can act as a signal of callose deposition for S. avenae resistance. This study will extend our understanding of aphid–wheat interaction and provides new insights in aphid-resistance wheat breeding.

scholarly journals Expression of genes encoding polyphenol oxidase and phenylalanine ammonia-lyase in wheat in response to Oulema spp. larvae feeding

2021 ◽  
Vol 61 (4) ◽  
pp. 308-318
Keyword(s):  
Plant Protection ◽  
Plant Defence ◽  
Mechanical Damage ◽  
Leaf Beetle ◽  
Point Of View ◽  
Stress Factors ◽  
Wheat Varieties ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Metabolites Production

Cereal leaf beetle (CLB, Oulema spp.) are economically important pests of cereals, because their feeding, especially at the larval stage may significantly reduce the quality and quantity of the obtained crop. The aim of the study was explanation the expression level of PPO and PAL genes involved in the secondary metabolites production in response to feeding of CLB larvae with a reduced or not reduced bacterial component. It was indicated that bacteria associated with CLB larvae supressed wheat response to CLB feeding to the benefit of insect host. Each of the three wheat varieties developed a unique defence mechanism against tested stress factors (including mechanical damage or damage caused by larvae feeding). The Arkadia variety reacted much faster and stronger to treatments in comparison to the other two wheat varieties. Understanding of the expression of genes involved in the plant defence response against herbivory pests is very important from an ecological point of view and has a great potential for use in plant protection.

Microbial elicitors of plant defence responses activate transcription of a retrotransposon

1994 ◽  
Vol 5 (4) ◽  
pp. 535-542 ◽  
Author(s):  
Sylvie Pouteau ◽  
Marie-Angele Grandbastien ◽  
Martine Boccara
Keyword(s):  
Plant Defence ◽  
Defence Responses ◽  
Plant Defence Responses

Hydrogen peroxide generated by over-expression of cytosolic superoxide dismutase in transgenic plums enhances bacterial canker resistance and modulates plant defence responses

2020 ◽  
Vol 47 (8) ◽  
pp. 5889-5901
Author(s):  
Mohamed Faize ◽  
Lydia Faize ◽  
Nuria Alburquerque ◽  
Jean Stéphane Venisse ◽  
Lorenzo Burgos
Keyword(s):  
Hydrogen Peroxide ◽  
Superoxide Dismutase ◽  
Plant Defence ◽  
Bacterial Canker ◽  
Over Expression ◽  
Defence Responses ◽  
Plant Defence Responses

scholarly journals Activation of Local and Systemic Defence Responses by Flg22 Is Dependent on Daytime and Ethylene in Intact Tomato Plants

2021 ◽  
Vol 22 (15) ◽  
pp. 8354
Author(s):  
Zalán Czékus ◽  
András Kukri ◽  
Kamirán Áron Hamow ◽  
Gabriella Szalai ◽  
Irma Tari ◽  
...  
Keyword(s):  
Stomatal Closure ◽  
Plant Defence ◽  
Time Of Day ◽  
Light Period ◽  
Ethylene Response Factor ◽  
Wild Type ◽  
Tomato Plants ◽  
Production Of Hydrogen ◽  
Pathogenesis Related ◽  
Defence Responses

The first line of plant defence responses against pathogens can be induced by the bacterial flg22 and can be dependent on various external and internal factors. Here, we firstly studied the effects of daytime and ethylene (ET) using Never ripe (Nr) mutants in the local and systemic defence responses of intact tomato plants after flg22 treatments. Flg22 was applied in the afternoon and at night and rapid reactions were detected. The production of hydrogen peroxide and nitric oxide was induced by flg22 locally, while superoxide was induced systemically, in wild type plants in the light period, but all remained lower at night and in Nr leaves. Flg22 elevated, locally, the ET, jasmonic acid (JA) and salicylic acid (SA) levels in the light period; these levels did not change significantly at night. Expression of Pathogenesis-related 1 (PR1), Ethylene response factor 1 (ERF1) and Defensin (DEF) showed also daytime- and ET-dependent changes. Enhanced ERF1 and DEF expression and stomatal closure were also observable in systemic leaves of wild type plants in the light. These data demonstrate that early biotic signalling in flg22-treated leaves and distal ones is an ET-dependent process and it is also determined by the time of day and inhibited in the early night phase.

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