Adult Leaf Research Articles

Genotyping of Ukrainian common wheat cultivars using the marker of the Lr48 gene conferring moderate resistance to leaf rust

Aim. Common wheat (Triticum aestivum L.) is one of the most important and widely cultivated crops over the world. For a lot of wheat diseases introduction of resistance genes is considered to be the most rational way to diminish yield losses and control spread of causal agents. The aim of this research was to study a sample of Ukrainian common wheat cultivars with the use of the molecular genetic marker for the Lr48 gene. Methods. DNA samples of 46 common wheat cultivars developed in the Remeslo Myronivka Institute of Wheat (RMIW) of National Academy of Agrarian Sciences jointly with the Institute of Plant Physiology and Genetics of National Academy of Sciences of Ukraine were analyzed with the use of the marker IWB70147. Results. It was revealed that 15 out of 46 (or 32.6 %) cultivars carried resistance-associated allele of the marker. Conclusions. It was revealed that the resistance-associated allele of the marker of the Lr48 gene is present in Ukrainian common wheat cultivars developed in the Forrest Steppe zone of Ukraine. The possible source of the resistance allele is „Mironovskaya 808‟ which is in the pedigree of many Ukrainian and world wheat cultivars. The data obtained in this research can be used in breeding programs to select sources of moderate adult plant resistance. Cultivars „Yuviliar Myronivskii‟, „Volodarka‟ and „Pamyati Remesla‟ with adult leaf rust resistance conferred by the Lr48 gene also carry resistance associated allele of the Lr34/Yr18/Pm38/Sr57/Bdv1 gene.Keywords: molecular markers, wheat, resistance genes, adult plant resistance.

Mapping a gene on wheat chromosome 4BL involved in a complementary interaction with adult plant leaf rust resistance gene LrSV2.

A complementary gene to LrSV2 for specific adult plant leaf rust resistance in wheat was mapped on chromosome 4BL, tightly linked to Lr12 / 31. LrSV2 is a race-specific adult plant leaf rust (Puccinia triticina) resistance gene on subdistal chromosome 3BS detected in the cross of the traditional Argentinean wheat (Triticum aestivum) variety Sinvalocho MA and the experimental line Gama6. The analysis of the cross of R46 [recombinant inbred line (RIL) derived from Sinvalocho MA carrying LrSV2 gene and the complementary gene Lrc-SV2 identified in the current paper] and the commercial variety Relmo Siriri (not carrying neither of these two genes) allowed the detection of the unlinked complementary gene Lrc-SV2 because the presence of one dominant allele of both is necessary to express the LrSV2-specific adult plant resistance. Lrc-SV2 was mapped within a 1-cM interval on chromosome 4BL using 100 RILs from the cross Sinvalocho MA × Purple Straw. This genetic system resembles the Lr27+31 seedling resistance reported in the Australian varieties Gatcher and Timgalen where interacting genes map at similar chromosomal positions. However, in high-resolution maps, Lr27 and LrSV2 were already mapped to adjacent intervals on 3BS and Lrc-SV2 map position on 4BL is distal to the reported Lr12/31-flanking microsatellites.

Semiochemical-Based Management of the Pea Leaf Weevil (Coleoptera: Curculionidae)

The pea leaf weevil, Sitona lineatus L. (Coleoptera: Curculionidae), is an important pest of pulse crops around the world. Adult pea leaf weevils rely on intra- and interspecific chemical cues to orient within their environment for the purposes of finding food and mates. Early research to identify semiochemical cues used by pea leaf weevils has permitted the development of semiochemical-baited traps that can reliably detect local movements and geographic range expansion of this species even at low population densities. More research is required to realize the potential of semiochemical-based management of the pea leaf weevil.The goals of this review are to: 1) introduce the chemical ecology of the pea leaf weevil and other Sitona species; 2) review the research conducted on semiochemical-based management of the pea leaf weevil in different growing regions; and 3) evaluate important areas of future research in both basic and applied chemical ecology of this pest.

The role of plant functional traits in understanding forest recovery in wet tropical secondary forests

Simultaneous measurement of plant functional traits and the regeneration environment should shed light on the plant-environment interactions and feedbacks as secondary forest regenerates. However, little of such work has been done in the wet tropics, and even fewer studies have examined soil nutrients. We investigated whether plant functional traits and environmental variables explain the varied recovery of secondary forests in Singapore. Our study plots included three primary forest plots and eight approximately 60-year-old secondary forest plots regenerating from intensive agricultural activities. Using 35 seedling quadrats, we asked: Q1) How do environmental variables explain the variation in seedling functional traits observed in primary and secondary forests? Q2) How do seedling traits, adult traits and environmental variables relate and explain variation in species richness and stem density in secondary forests? We found that both light and soil fertility explained the shifts in plants functional traits from poorly recovering secondary forests to primary forests. Poor forest regrowth was correlated with high soil aluminum levels and lower leaf nitrogen concentrations. Low nutrients and high aluminum saturation were also negatively correlated with seedling species richness, but not stem density, in the secondary forests. Forest recovery is probably slowed by positive feedback between slower nutrient returns from slow decaying litter and further recruitment of nutrient conserving species, as indicated by positive correlations among adult leaf CN ratio, litter depth, soil CN ratio and quadrat level CN ratio. Plant functional traits are indicative of the strategies of successful seedlings and do not necessarily relate to overall forest recovery. Hence, while some specialist plant species are able to accrue high nutrients on degraded soils with aluminum toxicity and low nutrients, species richness on these soils was poor. This underscores the need to concurrently measure environmental variables and plant traits when investigating the mechanisms driving changes during forest recovery.

Chewing Holes for Camouflage.

Camouflaged objects are harder to detect if the background itself is more heterogeneous, and search becomes increasingly inefficient when the scene contains multiple items resembling the target. Some adult leaf beetles (Coleoptera: Chrysomelidae) with highly specialized habits make holes on host plant leaves while feeding. We propose that leaf beetles camouflage themselves with their feeding holes. The presence of holes makes predators' visual search harder, thus giving beetles more time to escape from the leaf surface either by jumping (Galerucinae: Alticini) or rolling (rest of Chrysomelidae). Based on behavioral observations and analysis of 25 photographs of feeding leaf beetles (15 species), we demonstrate that adult leaf beetles camouflage themselves by creating holes of uniform size, approximately half of the beetle body size. Observation of the feeding behavior and anatomy of a typical hole-feeding beetle (Altica cirsicola) showed that the foregut volume and head-prothorax mobility of beetles are the two major factors that constrain the hole size. A computer-simulated visual search test showed that the greater the number of holes, and the more each hole approached beetle body size, the longer it took humans (as models) to locate a beetle on a leaf. This study reports a newly discovered kind of camouflage, hole-feeding camouflage, in leaf beetles, which makes visual detection or recognition more difficult by changing the environmental background. This type of camouflage may open up a range of new possibilities for studies in animal cognition analysis and evolution of anti-predation defenses.

Mapping and characterization of the new adult plant leaf rust resistance gene Lr77 derived from Santa Fe winter wheat.

A new gene for adult plant leaf rust resistance in wheat was mapped to chromosome 3BL. This gene was designated as Lr77. 'Santa Fe' is a hard red winter cultivar that has had long-lasting resistance to the leaf rust fungus, Puccinia triticina. The objective of this study was to determine the chromosome location of the adult plant leaf rust resistance in Santa Fe wheat. A partial backcross line of 'Thatcher' (Tc) wheat with adult plant leaf rust resistance derived from Santa Fe was crossed with Thatcher to develop a Thatcher//Tc*2/Santa Fe F6 recombinant inbred line (RIL) population. The RIL population and parental lines were evaluated for segregation of leaf rust resistance in three field plot tests and in an adult plant greenhouse test. A genetic map of the RIL population was constructed using 90,000 single-nucleotide polymorphism (SNP) markers with the Illumina Infinium iSelect 90K wheat bead array. A significant quantitative trait locus for reduction of leaf rust severity in all four tests was found on chromosome 3BL that segregated as a single adult plant resistance gene. The RILs with the allele from the resistant parent for SNP marker IWB10344 had lower leaf rust severity and a moderately resistant to moderately susceptible response compared to the susceptible RILs and Thatcher. The gene derived from Santa Fe on chromosome 3BL was designated as Lr77. Kompetitive allele-specific polymerase chain reaction assay markers linked to Lr77 on 3BL should be useful for selection of wheat germplasm with this gene.

Cadmium uptake kinetics in parts of the seagrass Cymodocea nodosa at high exposure concentrations

BackgroundSeagrass species have been recommended as biomonitors of environmental condition and as tools for phytoremediation, due to their ability to concentrate anthropogenic chemicals. This study aims to provide novel information on metal accumulation in seagrasses under laboratory conditions to support their use as a tool in the evaluation and abatement of contamination in the field. We investigated the kinetics of cadmium uptake into adult leaf blades, leaf sheaths, rhizomes and roots of Cymodocea nodosa in exposure concentrations within the range of cadmium levels in industrial wastewater (0.5–40 mg L−1).ResultsA Michaelis–Menten-type equation satisfactorily described cadmium accumulation kinetics in seagrass parts, particularly at 0.5–5 or 10 mg L−1. However, an S equation best described the uptake kinetics in rhizomes at 5 mg L−1 and roots at 10 and 20 mg L−1. Equilibrium concentration and uptake rate tended to increase with the exposure concentration, indicating that seagrass displays a remarkable accumulation capacity of cadmium and reflect high cadmium levels in the surrounding medium. Concerning leaf blades and rhizomes, the bioconcentration factor at equilibrium (range 73.3–404.3 and 14.3–86.3, respectively) was generally lower at higher exposure concentrations, indicating a gradual reduction of available binding sites. Leaf blades and roots accumulated more cadmium with higher rate than sheaths and rhizomes. Uptake kinetics in leaf blades displayed a better fit to the Michaelis–Menten-type equation than those in the remaining plant parts, particularly at 0.5–10 mg L−1. A marked variation in tissue concentrations mainly after the steady state was observed at 20 and 40 mg L−1, indicative of the stress induced on seagrass cells. The maximum concentrations observed in seagrass parts at 5 and 10 mg L−1 were comparatively higher than those previously reported for other seagrasses incubated to similar exposure concentrations.ConclusionsCymodocea nodosa displays a remarkable cadmium accumulation capacity and reflects high cadmium levels in the surrounding medium. Kinetic models satisfactorily describe cadmium uptake in seagrass parts, primarily in adult leaf blades, at high exposure concentrations, permitting to predict cadmium accumulation in field situations. Cymodocea nodosa appeared to be a valuable tool in the evaluation and abatement of cadmium contamination in coastal areas.

Adult plant leaf rust resistance derived from the wheat landrace cultivar Americano 44d is conditioned by interaction of three QTL

Americano 44 is a landrace derived wheat cultivar from Uruguay that has had long lasting resistance to the leaf rust pathogen Puccinia triticina. A population of 92 recombinant inbred lines derived from the cross ‘Thatcher*3/Americano 44d’ was evaluated for segregation of adult plant leaf rust resistance in four field plot tests and two greenhouse tests. A genetic map was constructed with 381 Diversity Array Technology markers, five simple sequence repeat markers, and seven kompetitive allele specific PCR markers. Significant effects for reduction of leaf rust severity were found for quantitative trait loci (QTL) on chromosomes 3AS, 3DS and 6DS. Individually the 3AS and 3DS regions did not decrease leaf rust severity in any of the tests compared to the susceptible parent, yet strongly interacted when present in the same genotype to decrease leaf rust severity equal to the resistant parent. Genotypes with only the 6DS region had significantly lower leaf rust severity compared to the susceptible parent in three of the field plot tests. The 6DS QTL also interacted with the 3DS QTL to decrease leaf rust severity. Major QTLs on chromosome 3AS and 3DS are both located in the distal region and may be encoded by homoeoalleles.

Associations among arbuscular mycorrhizal fungi and seedlings are predicted to change with tree successional status.

Arbuscular mycorrhizal (AM) fungi in the soil may influence tropical tree dynamics and forest succession. The mechanisms are poorly understood, because the functional characteristics and abundances of tree species and AM fungi are likely to be codependent. We used generalized joint attribute modeling to evaluate if AM fungi are associated with three forest community metrics for a sub-tropical montane forest in Puerto Rico. The metrics chosen to reflect changes during forest succession are the abundance of seedlings of different successional status, the amount of foliar damage on seedlings of different successional status, and community-weighted mean functional trait values (adult specific leaf area [SLA], adult wood density, and seed mass). We used high-throughput DNA sequencing to identify fungal operational taxonomic units (OTUs) in the soil. Model predictions showed that seedlings of mid- and late-successional species had less leaf damage when the 12 most common AM fungi were abundant compared to when these fungi were absent. We also found that seedlings of mid-successional species were predicted to be more abundant when the 12 most common AM fungi were abundant compared to when these fungi were absent. In contrast, early-successional tree seedlings were predicted to be less abundant when the 12 most common AM fungi were abundant compared to when these fungi were absent. Finally, we showed that, among the 12 most common AM fungi, different AM fungi were correlated with functional trait characteristics of early- or late-successional species. Together, these results suggest that early-successional species might not rely as much as mid- and late-successional species on AM fungi, and AM fungi might accelerate forest succession.

Leaf litter is essential for seed survival of the endemic endangered tree <i>Pouteria splendens</i> (Sapotaceae) from central Chile

Abstract. Pouteria splendens (A.DC.) Kuntze, the Chilean lúcumo, is an endemic tree and the only member of the Sapotaceae family in Chile. It is considered an endangered species as a consequence of its restricted distribution and small population size. Currently, individuals of P. splendens are immersed in a heterogeneous landscape with rocky mounds and plains located in areas densely populated by humans. Natural regeneration in the species seems to be low, despite the fact that plants are able to produce fruits. The species produces brightly colored fleshy drupes. There is no information about the dispersal pattern and the fate of the seeds. In this work we investigate (i) the seed dispersal pattern and (ii) the effect of tree canopy and the presence of leaf litter on seed survival, both in rocky mounds and plains. Results indicated an extremely low distance of seed dispersal, with most of the seeds falling down under the canopy. Seed survival under the canopy without leaf litter was very low and even zero in rocky mounds. Nevertheless, the presence of leaf litter covering the seeds increased survival in both habitats. Outside the canopy, seed survival only increased in plains. We suggest that future conservation programs should focus on protecting both adult plants and leaf litter under trees.

Adult Plant Leaf Rust Resistance Derived from Toropi Wheat is Conditioned by Lr78 and Three Minor QTL.

Leaf rust caused by Puccinia triticina is an important disease of wheat in many regions worldwide. Durable or long-lasting leaf rust resistance has been difficult to achieve because populations of P. triticina are highly variable for virulence to race-specific resistance genes, and respond to selection by resistance genes in released wheat cultivars. The wheat cultivar Toropi, developed and grown in Brazil, was noted to have long-lasting leaf rust resistance that was effective only in adult plants. The objectives of this study were to determine the chromosome location of the leaf rust resistance genes derived from Toropi in two populations of recombinant inbred lines in a partial Thatcher wheat background. In the first population, a single gene with major effects on chromosome 5DS that mapped 2.2 centimorgans distal to IWA6289, strongly reduced leaf rust severity in all 3 years of field plot tests. This gene for adult plant leaf rust resistance was designated as Lr78. In the second population, quantitative trait loci (QTL) with small effects on chromosomes 1BL, 3BS, and 4BS were found. These QTL expressed inconsistently over 4 years of field plot tests. The adult plant leaf rust resistance derived from Toropi involved a complex combination of QTL with large and small effects.

Adult Plant Leaf Rust Resistance Derived from the Soft Red Winter Wheat Cultivar ‘Caldwell’ Maps to Chromosome 3BS

ABSTRACT‘Caldwell’ is a US soft red winter wheat (Triticum aestivum L.) that has partial, adult plant resistance to the leaf rust pathogen Puccinia triticina Eriks. A line of ‘Thatcher∗2/Caldwell’ with adult plant resistance derived from Caldwell was crossed with ‘Thatcher’ to develop a population of recombinant inbred lines (RILs). The parents and RIL population were evaluated for segregation of leaf rust resistance in four field tests. A genetic map of the RIL population was constructed using 90K single‐nucleotide polymorphism (SNP) markers with the Illumina Infinium iSelect 90K wheat bead array. Significant effects for reduction of leaf rust severity in all four tests were found for a quantitative trait locus on chromosome 3BS. Simple sequence repeat (SSR) markers linked to the adult plant resistance gene Lr74 and kompetitive allele specific polymerase chain reaction (KASP) assay markers were added to the map on chromosome 3BS. Thatcher and the resistant Thatcher∗2/Caldwell parent were negative for the presence of Sr2 on chromosome 3BS based on the tightly linked marker csSr2. The SSR marker cfb5006 linked closely to Lr74 mapped the closest to the logarithm of odds peak for leaf rust resistance on chromosome 3BS. The SNP and SSR markers on chromosome 3BS can be used to add Caldwell leaf rust resistance to wheat breeding germplasm.

Effects of Three Parastagonospora nodorum Necrotrophic Effectors on Spring Wheat under Norwegian Field Conditions

ABSTRACTThe wheat (Triticum aestivum L.) disease Septoria nodorum blotch (SNB) is caused by the necrotrophic fungus Parastagonospora nodorum (Berk.) Quaedvlieg, Verkley & Crous and causes significant yield and quality losses in several wheat growing regions. The resistance mechanisms are quantitative and progress in resistance breeding has been slow. However, gene‐for‐gene interactions involving necrotrophic effectors (NEs) and sensitivity genes (Snn) are involved, providing hope for more effective breeding. Although the interactions are significant determinants of seedling SNB susceptibility, their role in adult plant leaf blotch resistance in the field is less understood. In this study, the frequency of SnTox genes was investigated in 62 P. nodorum isolates collected in Norway. A panel of Norwegian and international spring wheat lines and cultivars was screened under natural SNB infection in a mist‐irrigated field nursery across 7 yr. The lines were infiltrated in the greenhouse with the purified NEs SnToxA, SnTox1, and SnTox3, and the prevalence of corresponding sensitivity was investigated, as well as correlation between NE sensitivity and resistance level in the field. The frequencies of SnToxA, SnTox1, and SnTox3 in the isolates were 0.69, 0.53 and 0.76, respectively. Sensitivity to SnToxA, SnTox1, and SnTox3 was present in 45, 12, and 55% of the plant material. Sensitivity to SnToxA was associated with significantly higher disease severity in the field than insensitivity. This indicates that elimination of SnToxA sensitivity in the breeding material by effector infiltrations or marker‐assisted selection can be an effective way to increase field resistance to SNB.

Leaf heteroblasty in eucalypts: biogeographic evidence of ecological function

Leaves that develop on seedlings, young saplings or regenerative shoots of many eucalypt species are strikingly different in morphology from the typical leaves of more mature plants; a developmental pattern known as heteroblasty. We measured dimorphism between juvenile and adult leaves in shape and size, leaf mass per unit area, and vein frequency in a continent-wide sample of Angophora, Corymbia and Eucalyptus species. We tested whether heteroblasty in this group is an adaptation to shading by comparing the degree of juvenile–adult leaf dimorphism with the canopy closure (measured by the leaf area index) of the habitat in which species occurred. No pattern emerged for heteroblasty in leaf shape and size or leaf mass per unit area, but there was a significant relationship (accounting for phylogenetic relationships) between the degree of juvenile–adult dimorphism in vein frequency and habitat leaf area index. Juvenile leaves tended to have more widely spaced veins than adult leaves of the same species, in regions with more closed vegetative canopies. This evidence suggests that eucalypt heteroblasty is, at least in part, a hydraulic adaptation to the different conditions faced by younger and older plants in higher productivity regions with denser vegetation.

Screening of escherichia coli o157: H7 contamination and nitrate content on butterhead lettuce from market outlets

Escherichia coli O157:H7 is classified as biological hazard that can produce a bloody diarrhea due to its toxins. While nitrate in vegetables is classified as a chemical hazard if ingested greater than limit and risk getting gastrointestinal cancer and methemoglobinaemia. A study was conducted to obtain the information on E. coli O157:H7 contamination and nitrate content in Butterhead lettuce from local suppliers. The number of colonies E. coli O157:H7 from the lettuce was enumerated using standard plate count and the nitrate content was measured using nitrate meter. From the experiment, it was found that E. coli O157:H7 contamination of Butterhead lettuce in Malaysia is still within the safe limit for the consumers while the nitrate content was distributed differently between leaf structures; midrib, outer adult leaf blade and young leaves. Lettuce midrib and outer adult leaf blade had a higher concentration of nitrate compared to the young leaves.

Registration of ‘Norden’ Hard Red Spring Wheat

Grain yield, protein content, and straw strength are the three primary traits that growers consider when selecting wheat (Triticum aestivum L.) cultivars in the Red River Valley region of Minnesota and North Dakota. ‘Norden’ (Reg. No. CV‐1136, PI 667104) was released by the University of Minnesota Agricultural Experiment Station in 2012 because it represented a unique combination of these traits, in addition to good resistance to leaf rust (Puccinia triticina Eriks.) and Fusarium head blight (FHB, caused primarily by Fusarium graminearum Schwabe). Norden is a midmaturity, semidwarf cultivar that was selected in part because it contains the Lr34 gene for adult plant leaf rust resistance and the Fhb1 quantitative trait locus for FHB resistance.

Molecular introgression of leaf rust resistance gene Lr34 validates enhanced effect on resistance to spot blotch in spring wheat

The adult plant leaf rust resistance gene Lr34 was introduced using marker assisted selection (MAS) into an Indian wheat cultivar HUW510. Lr34 is associated with enhanced resistance to spot blotch. However, this effect has not been validated previously via introgression from one genetic background into another using MAS. The donor parent was the CIMMYT breeding line Picaflor#1. The morphological marker leaf tip necrosis (LTN+) and co-dominant STS marker csLV34 were used to track Lr34. Background selection was made with 90 simple sequence repeat (SSR) loci. BC3F3 to BC3F5 progenies were tested for spot blotch resistance. The results showed that the introgression of Lr34 can lead to enhanced resistance to spot blotch. Eleven selections retained in the cv. HUW510 background carried Lr34 and had a genetic background estimated to be as high as 95% that of the recurrent parent. The mean AUDPC for spot blotch in BC3F5 lines of Picaflor#1 × HUW510 was substantially lower (917 at timely sown conditions and 1015 under late sown conditions) than the recipient parent HUW510 (1332 at timely sown conditions and 1412 under late sown conditions). The results showed that introgression of Lr34 can lead to enhanced resistance to spot blotch.

Genetic architecture of adult plant resistance to leaf rust in a wheat association mapping panel

Leaf rust caused by Puccina triticina is one of the most destructive fungal diseases of wheat (Triticum aestivum). Adult plant resistance (APR) is an effective strategy to achieve long-term protection from the disease. In this study, findings are reported from a genome-wide association study (GWAS) using a panel of 96 wheat cultivars genotyped with 874 Diversity Arrays Technology (DArT) markers and tested for adult leaf rust response in six field trials. A total of 13 quantitative trait loci (QTL) conferring APR to leaf rust were identified on chromosome arms 1BL, 1DS, 2AS, 2BL, 2DS, 3BS, 3BL, 4AL, 6BS (two), 7DS, 5BL/7BS and 6AL/6BS. Of these, seven QTLs mapped close to known resistance genes and QTLs, while the remaining six are novel and can be used as additional sources of resistance. Accessions with a greater number of combined QTLs for APR showed lower levels of disease severity, demonstrating additive and significant pyramiding effects. All QTLs had stable main effects and they did not exhibit a significant interaction with the experiments. These findings could help to achieve adequate levels of durable resistance through marker-assisted selection and pyramiding resistance QTLs in local germplasm.

Behavioural adaptation of the rice leaf folder Cnaphalocrocis medinalis to short-term heat stress

Under ongoing climate warming, both the degree and number of high-temperature events in summer may increase, and behavioural adaptation is an important ecological strategy employed by insects to cope with such events. The rice leaf folder, Cnaphalocrocis medinalis Güenée, is a serious insect pest of rice fields in summer. Population outbreaks have become more frequent in the last ten years. In addition to adult migration, rice leaf folders are thought to have other thermal adaptations. Therefore, the behaviours of larval and adult rice leaf folders, such as leaf folding (making shelter) and habitat selection for pupae and eggs, were observed on rice plants under heat stress. The results showed that larval shelter-making velocities significantly decreased during or after four hours of heat exposure, and shelter size decreased as the temperature increased. Larvae preferred to pupate on young rice leaves at 27°C and middle-aged leaves at 30°C, but they strongly preferred older leaves when reared at 34°C. Female moths generally preferred to oviposit on the top of young leaves, but they preferred the middle and lower leaves for egg deposition when exposed to 36 and 40°C, respectively. Furthermore, more eggs were distributed on the lower surfaces of rice leaves with an increase in heat stress. These behavioural responses of rice leaf folders to heat stress indicate that this pest has great potential to adapt to high temperatures; therefore, the possibility of a population outbreak will remain high despite global warming.

Atmospheric Pressure Pulsed Plasma Induces Cell Death in Photosynthetic Organs via Intracellularly Generated ROS

The toxicity of atmospheric-pressure pulsed plasma on plant leaf tissues is studied. A nanosecond-pulsed plasma jet is applied to Arabidopsis thaliana leaves. In case of cotyledon, cell death is induced by treatment of only a few seconds. Cell death is also induced in the adult leaf by only 5 seconds of plasma treatment. Plasma induced reactive oxygen species (ROS) accumulation across the tissues within plasma-treated area. Plasma also induced direct physical damage to epidermis tissue of treated area but merely no damage to mesophyll. Thus, we propose direct physical damage in epidermis and ROS accumulation across the treated area induced cell death by plasma treatment. Plasma treatment with same duration in different organ also induced ROS accumulation but not plant death, suggests damage on photosynthetic organ by oxidative stress might be direct reason to induce cell death. We could also observe similar plasma induced death in Solanum esculentum, Petunia axillaris, and Nicotiana benthamiana but death is induced only in treated area. Thus, we propose atmospheric plasma induce oxidative stress in photosynthetic organ to induce cell death in plants.