scholarly journals The Effectiveness of Physical and Chemical Defense Responses of Wild Emmer Wheat Against Aphids Depends on Leaf Position and Genotype

2021 ◽  
Vol 12 ◽  
Author(s):  
Anuradha Singh ◽  
Brian Dilkes ◽  
Hanan Sela ◽  
Vered Tzin
Keyword(s):  
Chemical Defense ◽  
Defense Mechanisms ◽  
Aphid Resistance ◽  
Wild Emmer ◽  
Leaf Position ◽  
Trichome Density ◽  
Aphid Infestation ◽  
Phloem Sap ◽  
Physical Defense ◽  
Aphid Feeding

The bird cherry-oat aphid (Rhopalosiphum padi) is one of the most destructive insect pests in wheat production. To reduce aphid damage, wheat plants have evolved various chemical and physical defense mechanisms. Although these mechanisms have been frequently reported, much less is known about their effectiveness. The tetraploid wild emmer wheat (WEW; Triticum turgidum ssp. dicoccoides), one of the progenitors of domesticated wheat, possesses untapped resources from its numerous desirable traits, including insect resistance. The goal of this research was to determine the effectiveness of trichomes (physical defense) and benzoxazinoids (BXDs; chemical defense) in aphid resistance by exploiting the natural diversity of WEW. We integrated a large dataset composed of trichome density and BXD abundance across wheat genotypes, different leaf positions, conditions (constitutive and aphid-induced), and tissues (whole leaf and phloem sap). First, we evaluated aphid reproduction on 203 wheat accessions and found large variation in this trait. Then, we chose eight WEW genotypes and one domesticated durum wheat cultivar for detailed quantification of the defense mechanisms across three leaves. We discovered that these defense mechanisms are influenced by both leaf position and genotype, where aphid reproduction was the highest on leaf-1 (the oldest), and trichome density was the lowest. We compared the changes in trichome density and BXD levels upon aphid infestation and found only minor changes relative to untreated plants. This suggests that the defense mechanisms in the whole leaf are primarily anticipatory and unlikely to contribute to aphid-induced defense. Next, we quantified BXD levels in the phloem sap and detected a significant induction of two compounds upon aphid infestation. Moreover, evaluating aphid feeding patterns showed that aphids prefer to feed on the oldest leaf. These findings revealed the dynamic response at the whole leaf and phloem levels that altered aphid feeding and reproduction. Overall, they suggested that trichomes and the BXD 2,4-dihydroxy-7- methoxy-1,4-benzoxazin-3-one (DIMBOA) levels are the main factors determining aphid resistance, while trichomes are more effective than BXDs. Accessions from the WEW germplasm, rich with trichomes and BXDs, can be used as new genetic sources to improve the resistance of elite wheat cultivars.

Interrelationship between Quinolizidine Alkaloid Producing Legumes and Infesting Insects: Exploitation of the Alkaloid- Containing Phloem Sap of Cytisus scoparius by the Broom Aphid Aphis cytisorum

1982 ◽  
Vol 37 (11-12) ◽  
pp. 1081-1086 ◽  
Author(s):  
Michael Wink ◽  
Thomas Hartmann ◽  
Ludger Witte ◽  
Joachim Rheinheimer
Keyword(s):  
Direct Evidence ◽  
Xylem Sap ◽  
Aphid Resistance ◽  
Alkaloid Content ◽  
Quinolizidine Alkaloids ◽  
Cytisus Scoparius ◽  
Aphid Infestation ◽  
Phloem Sap ◽  
Quinolizidine Alkaloid ◽  
Evidence Analysis

Abstract Aphids (Aphis cytisorum) which infest broom plants (Cytisus scoparius) accumulate up to 500 μg alkaloid/g fr. wt. The alkaloids, which are similar to those of the plants, consist of 17-oxo-sparteine, sparteine, 12,13-dehydrosparteine, and lupanine. Infested plants contain > 50% less alkaloids than aphid-free plants. In Lupinus aphid resistance which is due to their high alkaloid content is more expressed: Whereas bitter varieties are free from aphids, only the sweet alkaloid-free plants are susceptible to aphid infestation. The accumulation of alkaloids in aphids indicates that the quinolizidine alkaloids are translocated via the phloem in legume plants. This assumption is supported by direct evidence: analysis of phloem sap from Lupinus contains up to 5 mg alkaloid whereas xylem sap is virtually free of alkaloids. The interrelationship between quinolizidine alkaloids and hervivores is discussed.

scholarly journals Variation Between Three Eragrostis tef Accessions in Defense Responses to Rhopalosiphum padi Aphid Infestation

2020 ◽  
Vol 11 ◽  
Author(s):  
Nathan M. Gyan ◽  
Beery Yaakov ◽  
Nati Weinblum ◽  
Anuradha Singh ◽  
Alon Cna’ani ◽  
...  
Keyword(s):  
Stress Responses ◽  
Defense Mechanisms ◽  
Rhopalosiphum Padi ◽  
Defense Responses ◽  
The Other ◽  
Eragrostis Tef ◽  
Aphid Infestation ◽  
Volatile Analysis ◽  
Insect Order ◽  
Physical Defense

Tef (Eragrostis tef), a staple crop that originated in the Horn of Africa, has been introduced to multiple countries over the last several decades. Crop cultivation in new geographic regions raises questions regarding the molecular basis for biotic stress responses. In this study, we aimed to classify the insect abundance on tef crop in Israel, and to elucidate its chemical and physical defense mechanisms in response to insect feeding. To discover the main pests of tef in the Mediterranean climate, we conducted an insect field survey on three selected accessions named RTC-144, RTC-405, and RTC-406, and discovered that the most abundant insect order is Hemiptera. We compared the differences in Rhopalosiphum padi (Hemiptera; Aphididae) aphid performance, preference, and feeding behavior between the three accessions. While the number of aphid progeny was lower on RTC-406 than on the other two, the aphid olfactory assay indicated that the aphids tended to be repelled from the RTC-144 accession. To highlight the variation in defense responses, we investigated the physical and chemical mechanisms. As a physical barrier, the density of non-granular trichomes was evaluated, in which a higher number of trichomes on the RTC-406 than on the other accessions was observed. This was negatively correlated with aphid performance. To determine chemical responses, the volatile and central metabolite profiles were measured upon aphid attack for 4 days. The volatile analysis exposed a rich and dynamic metabolic profile, and the central metabolism profile indicated that tef plants adjust their sugars and organic and amino acid levels. Overall, we found that the tef plants possess similar defense responses as other Poaceae family species, while the non-volatile deterrent compounds are yet to be characterized. A transcriptomic time-series analysis of a selected accession RTC-144 infested with aphids revealed a massive alteration of genes related to specialized metabolism that potentially synthesize non-volatile toxic compounds. This is the first report to reveal the variation in the defense mechanisms of tef plants. These findings can facilitate the discovery of insect-resistance genes leading to enhanced yield in tef and other cereal crops.

scholarly journals Comparative transcriptomic and metabolic analysis of wild and domesticated wheat genotypes reveals differences in chemical and physical defense responses against aphids

2019 ◽  
Author(s):  
Zhaniya S Batyrshina ◽  
Beery Yaakov ◽  
Reut Shavit ◽  
Anuradha Singh ◽  
Vered Tzin
Keyword(s):  
Chinese Spring ◽  
Defense Mechanisms ◽  
Chemical Defenses ◽  
Wild Emmer ◽  
Primary Metabolism ◽  
Trichome Density ◽  
Wheat Seedlings ◽  
Wheat Genotypes ◽  
Physical Defenses ◽  
In The Wild

Abstract Background: Young wheat plants are continuously exposed to herbivorous insect attack. To reduce insect damage and maintain their growth, plants evolved different defense mechanisms, including the biosynthesis of deterrent compounds named benzoxazinoids, and/or trichome formation that provides physical barriers. It is unclear whether both of these mechanisms are equally critical in providing an efficient defense for wheat seedlings against aphids—an economically costly pest in cereal production. Results: In this study, we compared the transcriptome, metabolome, benzoxazinoids, and trichome density of three selected wheat genotypes, with a focus on differences related to defense mechanisms. We chose diverse wheat genotypes: two tetraploid wheat genotypes, domesticated durum ‘Svevo’ and wild emmer ‘Zavitan,’ and one hexaploid bread wheat, ‘Chinese Spring.’ The full transcriptomic analysis revealed a major difference between the three genotypes, while the clustering of significantly different genes suggested a higher similarity between the two domesticated wheats than between either and the wild wheat. A pathway enrichment analysis indicated that the genes associated with primary metabolism, as well as the pathways associated with defense such as phytohormones and specialized metabolites, were different between the three genotypes. Measurement of benzoxazinoid levels at the three time points (11, 15, and 18 days after germination) revealed high levels in the two domesticated genotypes, while in wild emmer wheat, they were below detection level. In contrast to the benzoxazinoid levels, the trichome density was dramatically higher in the wild emmer than in the domesticated wheat. Lastly, we tested the bird cherry-oat aphid’s ( Rhopalosiphum padi ) performance and found that Chinese Spring is more resistant than the tetraploid genotypes. Conclusions: Our results show that benzoxazinoids play a more significant defensive role than trichomes. Differences between the abundance of defense mechanisms in the wild and domesticated plants were observed in which wild emmer possesses high physical defenses while the domesticated wheat genotypes have high chemical defenses. These findings provide new insights into the defense adaptations of wheat plants against aphids.

Antibiosis and tolerance but not antixenosis to the grain aphid, Sitobion avenae (Hemiptera: Aphididae), are essential mechanisms of resistance in a wheat cultivar

2015 ◽  
Vol 105 (4) ◽  
pp. 448-455 ◽  
Author(s):  
H.-H. Cao ◽  
M.-Z. Pan ◽  
H.-R. Liu ◽  
S.-H. Wang ◽  
T.-X. Liu
Keyword(s):  
Wheat Cultivar ◽  
Sitobion Avenae ◽  
Intrinsic Rate Of Increase ◽  
Feeding Time ◽  
Wheat Cultivars ◽  
Aphid Infestation ◽  
Phloem Sap ◽  
Grain Aphid ◽  
Rate Of Increase ◽  
Aphid Feeding

AbstractContinuous ingestion of the phloem sap of plants by aphids can remove a significant amount of photoassimilates. Based on our earlier works, we hypothesized that due to the reduced aphid feeding time caused by antibiosis, wheat plants may achieve growth tolerance to aphids. We tested this hypothesis using three wheat cultivars, XY22 (Xiaoyan22), AK58 (Bainongaikang58) and XN979 (Xinong979) and the grain aphid, Sitobion avenae. In the choice test, S. avenae did not show any preference among the three wheat cultivars. However, S. avenae had a lower body weight and a lower intrinsic rate of increase when feeding on XY22 than on AK58 and XN979. The electrical penetration graph results indicated that S. avenae had significantly shorter mean and total phloem ingestion periods on XY22 than on AK58 or XN979. The aphids required a similar time to reach the phloem sap on the three wheat cultivars, but required more time to establish sustained phloem ingestion on XY22. These results suggest that the resistance factors of XY22 may be phloem based. Moreover, XY22 suffered less biomass loss in response to aphid infestation compared with XN979, suggesting that XY22 also had a better growth tolerance to S. avenae than XN979. Wheat resistance level to S. avenae was partially correlated with plant photosynthetic rates, and peroxidase activities. These results confirmed that the limitation in aphid feeding from plant phloem in wheat cultivar XY22 was related to antibiosis but not antixenosis, which caused XY22 tolerance to S. avenae.

scholarly journals Comparative transcriptomic and metabolic analysis of wild and domesticated wheat genotypes reveals differences in chemical and physical defense responses against aphids

2019 ◽  
Author(s):  
Zhaniya S Batyrshina ◽  
Beery Yaakov ◽  
Reut Shavit ◽  
Anuradha Singh ◽  
Vered Tzin
Keyword(s):  
Chinese Spring ◽  
Defense Mechanisms ◽  
Chemical Defenses ◽  
Wild Emmer ◽  
Primary Metabolism ◽  
Trichome Density ◽  
Wheat Seedlings ◽  
Wheat Genotypes ◽  
Physical Defenses ◽  
In The Wild

Abstract Background Young wheat plants are continuously exposed to herbivorous insect attack. To reduce insect damage and maintain their growth, plants evolved different defense mechanisms, including the biosynthesis of deterrent compounds named benzoxazinoids, and/or trichome formation that provides physical barriers. It is unclear whether both of these mechanisms are equally critical in providing an efficient defense for wheat seedlings against aphids—an economically costly pest in cereal production. Results: In this study, we compared the transcriptome, metabolome, benzoxazinoids, and trichome density of three selected wheat genotypes, with a focus on differences related to defense mechanisms. We chose diverse wheat genotypes: two tetraploid wheat genotypes, domesticated durum ‘Svevo’ and wild emmer ‘Zavitan,’ and one hexaploid bread wheat, ‘Chinese Spring.’ The full transcriptomic analysis revealed a major difference between the three genotypes, while the clustering of significantly different genes suggested a higher similarity between the two domesticated wheats than between either and the wild wheat. A pathway enrichment analysis indicated that the genes associated with primary metabolism, as well as the pathways associated with defense such as phytohormones and specialized metabolites, were different between the three genotypes. Measurement of benzoxazinoid levels at the three time points (11, 15, and 18 days after germination) revealed high levels in the two domesticated genotypes, while in wild emmer wheat, they were below detection level. In contrast to the benzoxazinoid levels, the trichome density was dramatically higher in the wild emmer than in the domesticated wheat. Lastly, we tested the bird cherry-oat aphid’s ( Rhopalosiphum padi ) performance and found that Chinese Spring is more resistant than the tetraploid genotypes. Conclusions: Our results show that benzoxazinoids play a more significant defensive role than trichomes. Differences between the abundance of defense mechanisms in the wild and domesticated plants were observed in which wild emmer possesses high physical defenses while the domesticated wheat genotypes have high chemical defenses. These findings provide new insights into the defense adaptations of wheat plants against aphids.

scholarly journals The green peach aphid Myzus persicae perform better on pre-infested Chinese cabbage Brassica pekinensis by enhancing host plant nutritional quality

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
He-He Cao ◽  
Hui-Ru Liu ◽  
Zhan-Feng Zhang ◽  
Tong-Xian Liu
Keyword(s):  
Chinese Cabbage ◽  
Myzus Persicae ◽  
Green Peach Aphid ◽  
Marker Genes ◽  
Plant Leaves ◽  
Resistance Level ◽  
Aphid Infestation ◽  
Phloem Sap ◽  
Brassica Pekinensis ◽  
Plant Nutritional Quality

Abstract The green peach aphid, Myzus persicae Sulzer, is a notorious pest on vegetables, which often aggregates in high densities on crop leaves. In this study, we investigated whether M. persicae could suppress the resistance level of Chinese cabbage Brassica pekinensis. M. persicae performed better in terms of weight gain (~33% increase) and population growth (~110% increase) when feeding on previously infested (pre-infested) Chinese cabbage compared with those on non-infested plants. However, when given a choice, 64% of the aphids preferred to settle on non-infested leaves, while 29% of aphids chose pre-infested leaves that had a 2.9 times higher concentration of glucosinolates. Aphid feeding significantly enhanced the amino acid:sugar ratio of phloem sap and the absolute amino acid concentration in plant leaves. Aphid infestation significantly increased the expression levels of salicylic acid (SA) marker genes, while it had marginal effects on the expression of jasmonate marker genes. Exogenously applied SA or methyl jasmonate had no significant effects on M. persicae performance, although these chemicals increased glucosinolates concentration in plant leaves. M. persicae infestation increase amino acid:sugar ratio and activate plant defenses, but aphid performed better on pre-infested plants, suggesting that both nutrition and toxics should be considered in insect-plant interaction.

scholarly journals Understanding the Plant Aphid Interaction: A Review

2021 ◽  
Vol 2 (6) ◽  
pp. 1-6
Author(s):  
Waghmare Kranti ◽  
Ghayal Nivedita ◽  
Mahesh Shindikar
Keyword(s):  
Host Plants ◽  
Indirect Defense ◽  
Genetically Engineered ◽  
Aphid Infestation ◽  
Aphid Control ◽  
Aphid Feeding ◽  
Strategic Ability ◽  
Genetically Engineered Crops ◽  
Plant Sap

The interaction between plant-aphid is phenomenal and complex. Aphids possess efficient mouthparts which feed on plant sap intensively. Adaptation to host plants and successful feeding is achieved through the strategic ability of aphids to reproduce sexually and asexually (parthenogenesis). Aphid infestation damages the plant in diverse ways and induces plant defense. Though plant elicit direct and indirect defense to resist aphid feeding, the effectiveness of plant resistance depends largely on the aphid infestation rate and quality of the host plant. To control aphid infestation and plant damage, dependency on insecticides is undesirable due to insecticidal resistance of aphids and environmental pollution. The approach towards the development of the genetically engineered crops which are aphid resistant can be the considerable potential to aphid control..

Biochemical markers of oxidative stress in maize seedlings exposed to rose-grass aphids

2021 ◽  
Vol 53 (1) ◽  
pp. 23-34
Author(s):  
I. Łukasik ◽  
S. Goławska
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Superoxide Anion ◽  
Biochemical Markers ◽  
Carbonyl Groups ◽  
Maize Seedlings ◽  
Aphid Infestation ◽  
Markers Of Oxidative Stress ◽  
Aphid Feeding ◽  
Superoxide Anion Radicals

We studied the influence of rose-grass aphid (Metopolophium dirhodum L.) infestation on the biochemical markers of oxidative stress in seedlings of two maize (Zea mays L.) varieties (relatively resistant Ambrozja and resistant Plomyk). We compared the generation of superoxide anion radicals O2-, level of hydrogen peroxide (H2O2), lipid peroxidation products (MDA) as well as markers of protein damage (protein-bound carbonyl groups). The studied parameters were measured at 24, 48, 72 and 96 h post-initial aphid infestation compared to the non-infested control seedlings. Our studies indicated that the rose-grass aphid feeding evoked oxidative stress in the maize seedlings. Investigated Z. mays cultivars exhibited excessive generation of superoxide anion radicals in response to insect treatments. Rose-grass aphid feeding increased the H2O2 level in maize tissues with similar levels observed at most periods post-infestation with M. dirhodum, also increased lipid peroxidation products with the maximal levels at 48 and 72 h for Ambrozja and 48, 72 and 96 h post-infestation for Plomyk varieties. Further at 48 and 72 h post-initial aphid infestation, there was an increase in protein bound carbonyl groups content in the maize seedlings after infestation with aphids.

Diuraphis noxia (Russian wheat aphid).

2021 ◽  
Author(s):  
Mohammad Reza Nematollahi
Keyword(s):  
Nutritional Quality ◽  
Essential Amino Acids ◽  
Diuraphis Noxia ◽  
Cereal Crops ◽  
Phloem Sap ◽  
Foliar Tissue ◽  
Aphid Feeding ◽  
Wheat Leaves ◽  
Phloem Feeder

Abstract D. noxia has a great economic impact on cereal crops (Brooks et al., 1994). It is a phloem feeder like other aphids and the symptoms evident on plants are a result of this feeding mechanism. By feeding on the phloem, the aphid damages the plants through nutrient drainage (Dixon, 1985) which results in chlorosis, necrosis, wilting, stunting, and curling of the leaves, misshapen or nonappearance of new growth, and localised cell death at the site of aphid feeding. D. noxia further elicits an increase in essential amino acids in the phloem sap by triggering the breakdown of proteins in infested wheat leaves (Burd and Burton, 1992; du Toit, 1986; Ma et al., 1998; Miller et al., 2001). The damage to the foliar tissue is thought to play a role in the pest's ability to increase nutritional quality of the host plant (Botha et al., 2006).

Aphid Resistance and Leaf Surface Chemistry of Sugar Ester Producing Tobaccos1

2002 ◽  
Vol 37 (2) ◽  
pp. 154-165 ◽  
Author(s):  
A. W. Johnson ◽  
V. A. Sisson ◽  
M. E. Snook ◽  
B. A. Fortnum ◽  
D. M. Jackson
Keyword(s):  
Surface Chemistry ◽  
Leaf Surface ◽  
Significant Negative Correlation ◽  
Aphid Resistance ◽  
Sugar Ester ◽  
Resistance Level ◽  
Aphid Infestation ◽  
Sugar Esters ◽  
Leaf Surface Chemistry ◽  
Different Types

Sugar ester producing tobacco lines were evaluated for aphid resistance and other surface chemicals. The cembrenoid and labdenoid diterpenes, α- and β-4,8,13-duvatrien-1-ols, α- and β-4,8,13-duvatriene-1,3-diols, (12Z)-labda-12,14-diene-8α-ol (cis-abienol), (13E)-labda-13-ene-8α,15-diol (labdenediol), docosanol, and sugar esters were quantified using high pressure liquid chromatography and compared with aphid infestation ratings. Regression analysis of aphid [Myzus persicae (Sulzer)] infestation rating and leaf surface chemistry was statistically significant and showed that surface chemicals were important in explaining the observed variation in the aphid infestation ratings. A significant negative correlation was found between aphid ratings and sugar ester levels among the 62 entries evaluated (r = −0.2758, P = 0.0301). α and β monols (α- and β-4,8,13-duvatrien-1-ols) were also significantly correlated with aphid infestations in this study (r = −0.2743, P = 0.0310 and r = −0.2797, P= 0.0109, respectively). None of the other surface chemicals were statistically correlated with aphid resistance. Although high sugar ester levels were correlated with aphid resistance, not all tobacco entries with high levels of sugar esters, such as Tl 1568 were resistant. This would suggest that there may be different types of sugar esters present in these tobaccos, and total sugar ester levels alone could not be used to predict aphid resistance. Also, some tobacco lines, like Tl 1674 and Tl 59 with lower sugar ester levels, were resistant in this study because of high monol levels. The ten tobacco entries with the highest levels of sugar esters in this study were Tl 698, Tl 675, Tl 704, Tl 998, Tl 193, JA 389, Tl 722R, Tl 1092, Tl 711, and Tl 1007. All of these lines exhibited high levels of aphid resistance, but some also had low-to-moderate levels of monols that may have elevated the aphid resistance level. A number of these tobaccos could be used for production of natural sugar ester biorationals or used in a breeding program for development of aphid resistant cultivars.

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