Dynamics in the activity of peroxidase and its isoforms in leaves of different apple cultivars

Background. Various approaches are used for identification of the most resistant fruit crop cultivars, including the analysis of different physiological and biochemical indicators. In Krasnodar Territory, Russia, one of the major stressors in summer is the hydrothermal stress. Drought and heat lead to an oxidative stress, as reactive oxygen species are produced in plant cells. Plants respond to oxidative damage by activating antioxidant enzymes, such as superoxide dismutase, catalase, and various peroxidases. Peroxidase is able to decompose hydrogen peroxide. Peroxidase activity was calculated under natural summertime changes in the hydrothermal pattern (control) and in simulated high-temperature conditions.Materials and methods. Three apple cultivars of Russian breeding, ‘Fortuna’, ‘Soyuz’ and ‘Prikubanskoe’, and cv. ‘Ligol’ of Polish origin were studied. In the summers of 2018–2019, their leaf samples were analyzed to assess peroxidase activity and its isozyme composition under control and stress conditions. Native electrophoresis in polyacrylamide gel was used for separation of peroxidase isoforms. Malondialdehyde content was measured to identify oxidative stress levels in apple leaves.Results. The tested indicators demonstrated a high degree of heterogeneity induced by both cultivar specificity and seasonal weather dynamics. Peroxidase isoforms with a molecular weight of 70 to 60 kDa, characterized by the maximum level of variability (1–4 isoforms), were isolated. Two other groups included 1–3 isoforms with a molecular weight of ~130–100 kDa, and one with a molecular weight of ~55 kDa. The highest enzyme activity was found in cvs. ‘Fortuna’ and ‘Soyuz’ in July 2018, the hottest month during the period of research. Under simulated conditions, the triploid cultivar ‘Soyuz’ was least susceptible to the stress impact.

Soil composition and plant genotype determine benzoxazinoid-mediated plant-soil feedbacks in cereals

Plant-soil feedbacks refer to effects on plants that are mediated by soil modifications caused by the previous plant generation. Maize conditions the surrounding soil by secretion of root exudates including benzoxazinoids (BXs), a class of bioactive secondary metabolites. Previous work found that a BX- conditioned soil microbiota enhances insect resistance while reducing biomass in the next generation of maize plants. Whether these BX-mediated and microbially driven feedbacks are conserved across different soils and response species is unknown. We found the BX-feedbacks on maize growth and insect resistance conserved between two arable soils, but absent in a more fertile grassland soil, suggesting a soil-type dependence of BX feedbacks. We demonstrated that wheat also responded to BX-feedbacks. While the negative growth response to BX-conditioning was conserved in both cereals, insect resistance showed opposite patterns, with an increase in maize and a decrease in wheat. Wheat pathogen resistance was not affected. Finally and consistent with maize, we found the BX-feedbacks to be cultivar specific. Taken together, BX- feedbacks affected cereal growth and resistance in a soil and genotype dependent manner. Cultivar-specificity of BX-feedbacks is a key finding, as it hides the potential to optimize crops that avoid negative plant-soil feedbacks in rotations.

The risk of wheat blast in rice-wheat-co-planting regions in China: MoO strains of Pyricularia oryzae cause typical symptom and host reaction on both wheat leaves and spikes

Triticum pathotype (MoT) of Magnaporthe oryzae (syn. Pyricularia oryzae) causes wheat blast, which has recently spread to Asia. To assess the potential risk of wheat blast in rice-wheat growing regions, we investigated the pathogenicity of 14 isolates of P. oryzae on 32 wheat cultivars, among which MoO isolates were completely avirulent on the wheat cultivars at 22℃, but caused various infection degrees at 25℃. These reactions at 25℃ were isolate- and cultivar- dependent like race-cultivar specificity which was also recognized at the heading stage and caused typical blast symptoms on spikes. Microscopic analyses indicated that a compatible MoO isolates produced appressoria and infection hyphae on wheat as on rice. By comparing transcriptomes in wheat-MoO interactions, a bulk of pathogen-related genes was up-/down- regulated in compatible and incompatible patterns, but that changes of gene transcription were more significant in compatible pattern. These results indicate that the temperature could influence the infection ratio of wheat with MoO, and some MoO strains could be potential pathogens that increase the risk for the outbreak of wheat blast in wheat-rice growing regions with global warming. In addition, certain wheat cultivars exhibited resistance and are assumed to carry promoting resistant genes to the MoO strains.

Correlations of polyphenolic substances in Ribes aureum Pursh (Grossulariaceae) fruits

The morphometric parameters of fruits (yield, weight) were revealed and the quantitative determination of anthocyanins and carotenoids in the fruits of golden currant (Ribes aureum Pursh) was carried out using the methods of spectrophotometry and reverse-phase high-performance liquid chromatography. The cultivar specificity in the content of anthocyanins and carotene in R. aureum fruits was established. There is a direct correlation between the anthocyanin and carotene content, which allows assessing the biological activity more accurately. No correlation was found between the morphometric and biochemical characteristics of R. aureum fruits.

iTRAQ-based Comparative Proteomic Analysis of Flag Leaves of Two Wheat (Triticum aestivum L.) Genotypes Differing in Waterlogging Tolerance at Anthesis

Background: Waterlogging is one of the major abiotic stresses limiting wheat product. Plants can adapt to waterlogging with changes in morphology, anatomy, and metabolism. Many genes and proteins play critical roles in adaptation to waterlogging. Results: the iTRAQ-based proteomic strategy was applied to identify the waterlogging-responsive proteins in wheat. A total of 4,999 unique proteins were identified in two wheat varieties, XM55 (waterlogging-tolerant) and YM158 (waterlogging-sensitive), at anthesis under waterlogging or not. Sixteen proteins were differentially accumulated between XM55 and YM158 under waterlogging with cultivar specificity. Of these, 11 proteins were up-regulated and 5 proteins were down-regulated. The up-regulated proteins included Fe-S cluster assembly factor, heat shock cognate 70, GTP-binding protein SAR1A-like, and CBS domain-containing protein. The down-regulated proteins contained photosystem II reaction center protein H, carotenoid 9,10 (9',10')-cleavage dioxygenase-like, psbP-like protein 1, and mitochondrial ATPase inhibitor. In addition, 9 proteins were responsive to waterlogging with non-cultivar specificity. These proteins included 3-isopropylmalate dehydratase large subunit, solanesyl-diphosphate synthase 2, DEAD-box ATP-dependent RNA helicase 3, and 3 predicted or uncharacterized proteins. Conclusions: This study revealed that the proteins were differential accumulated between the two contrast waterlogging wheat varieties in response to waterlogging, which provide valuable insights into wheat response to waterlogging stress. These differentially accumulated proteins might be applied to develop waterlogging tolerant wheat in further breeding programs.

Influence of plant immunity inducers on the degree of apple scab development when applied in plant protection systems in the zone of humid subtropics of Abkhazia

One of the ways to reduce pesticide load and prevent emergence of pathogen resistance can be the use of plant immunity inducers in plant protection systems. The purpose of these studies was to evaluate an efficiency of natural plant immunity inducers Albit® (poly-beta-hydroxybutyric acid), Immunocytophite® (arachidonic acid ethyl ether) and Ecogel® (chitosan lactate) in apple scab protection systems in Abkhazia. The maximum resistance of apple trees to this phytopathogen was recorded in the experimental variants with Albit® and Ecogel® application in half dosages of fungicides and in the variant of production processing (biological efficiency reached 79.4 %). Plant immunity inducers used on apple trees showed cultivar-specificity. For the four-year research period, the greatest efficiency of immunity inducers was achieved on the susceptible cultivar Idared in the second year of the experiment, while on the relatively scab-resistant cultivar Golden Rangers – it was achieved only in the third year. The greatest stability in the efficiency for a four-year period was observed for the tank mix Albit with half dosages of fungicides. Immunocytophyte® was characterized by lower inducing activity, which is associated with its activation of the jasmonate pathway for the formation of non-specific induced immunity.

iTRAQ-based Comparative Proteomic Analysis of Flag Leaves of Two Wheat (Triticum aestivum L.) Genotypes Differing in Waterlogging Tolerance at Anthesis

Background : Waterlogging is one of the major abiotic stresses limiting wheat product. Plants can adapt to waterlogging with changes in morphology, anatomy, and metabolism. Many genes and proteins play critical roles in adaptation to waterlogging. Results : the iTRAQ-based proteomic strategy was applied to identify the waterlogging-responsive proteins in wheat. A total of 7,710 proteins were identified in two wheat varieties, XM55 (waterlogging-tolerant) and YM158 (waterlogging-sensitive), at anthesis under waterlogging or not. Sixteen proteins were differentially accumulated between XM55 and YM158 under waterlogging with cultivar specificity. Of these, 11 proteins were up-regulated and 5 proteins were down-regulated. The up-regulated proteins included Fe-S cluster assembly factor, heat shock cognate 70, GTP-binding protein SAR1A-like, and CBS domain-containing protein. The down-regulated proteins contained photosystem II reaction center protein H, carotenoid 9,10 (9',10')-cleavage dioxygenase-like, psbP-like protein 1, and mitochondrial ATPase inhibitor. In addition, 9 proteins were responsive to waterlogging with non-cultivar specificity. These proteins included 3-isopropylmalate dehydratase large subunit, solanesyl-diphosphate synthase 2, DEAD-box ATP-dependent RNA helicase 3, and 3 predicted or uncharacterized proteins. Conclusion s: This study revealed that the proteins were differential accumulated between the two contrast waterlogging wheat varieties in response to waterlogging, which provide valuable insights into wheat response to waterlogging stress. These differentially accumulated proteins might be applied to develop waterlogging tolerant wheat in further breeding programs.

iTRAQ-based Comparative Proteomic Analysis of Flag Leaves of Two Wheat (Triticum aestivum L.) Genotypes Differing in Waterlogging Tolerance at Anthesis

Background : Waterlogging is one of the major abiotic stresses limiting wheat product. Plants can adapt to waterlogging with changes in morphology, anatomy, and metabolism. Many genes and proteins play critical roles in adaptation to waterlogging. Results : in this study, the iTRAQ-based proteomic strategy was applied to identify the waterlogging-responsive proteins in wheat. A total of 7,710 proteins were identified in two wheat varieties, XM55 (waterlogging-tolerant) and YM158 (waterlogging-sensitive), at anthesis under waterlogging or not. Sixteen proteins were differentially accumulated between XM55 and YM158 under waterlogging with cultivar specificity. Of these, 11 proteins were up-regulated and 5 proteins were down-regulated. The up-regulated proteins included Fe-S cluster assembly factor, heat shock cognate 70, GTP-binding protein SAR1A-like, and CBS domain-containing protein. The down-regulated proteins contained photosystem II reaction center protein H, carotenoid 9,10 (9',10')-cleavage dioxygenase-like, psbP-like protein 1, and mitochondrial ATPase inhibitor. In addition, 9 proteins were responsive to waterlogging with non-cultivar specificity. These proteins included 3-isopropylmalate dehydratase large subunit, solanesyl-diphosphate synthase 2, DEAD-box ATP-dependent RNA helicase 3, and 3 predicted or uncharacterized proteins. Sixteen out of the 28 selected proteins showed consistent expression patterns between mRNA and protein levels. Conclusion s: This study revealed that the proteins were differential accumulated between the two contrast waterlogging wheat varieties in response to waterlogging, which provide valuable insights into wheat response to waterlogging stress. The identified differentially accumulated protein might be applied to develop waterlogging tolerant wheat.

iTRAQ-based Comparative Proteomic Analysis of Flag Leaves of Two Wheat (Triticum aestivum L.) Genotypes Differing in Waterlogging Tolerance at Anthesis

Background Waterlogging is one of the major abiotic stresses limiting wheat product. Plants can adapt to waterlogging with changes in morphology, anatomy, and metabolism. A number of genes or proteins were responsive to waterlogging. Results in this sduty, the iTRAQ-based proteomic strategy was applied to identify waterlogging-responsive proteins in wheat. A total of 7710 proteins were identified in waterlogging tolerant and sensitive wheat varieties XM55 and YM158 at anthesis under waterlogging or not. Sixteen proteins were differentially accumulated between XM55 and YM158 under waterlogging with cultivar specificity. Among them, eleven proteins were up-regulated and five proteins were down-regulated. The up-regulated proteins included Fe-S cluster assembly factor, heat shock cognate 70, GTP-binding protein SAR1A-like, and CBS domain-containing protein. The down-regulated proteins contained photosystem II reaction center protein H, carotenoid 9,10 (9',10')-cleavage dioxygenase-like, psbP-like protein 1, and mitochondrial ATPase inhibitor. In addition, nine proteins were responsive to waterlogging with non-cultivar specificity. These proteins included 3-isopropylmalate dehydratase large subunit, solanesyl-diphosphate synthase 2, DEAD-box ATP-dependent RNA helicase 3, and three predicted or uncharacterized proteins. Sixteen out of the twenty-eight selected proteins showed consistent expression patterns between mRNA and protein levels by quantitative real-time PCR. Conclusions: Our study indicates the much proteins were differential accumulated between the two contrast waterlogging wheat varieties in response to waterlogging, which provide insight into wheat response to waterlogging stress. The identified differentially accumulated protein might be applied to develop waterlogging tolerant wheat.