Jorge A Zavala

University of Buenos Aires and National Scientific and Technical Research Council, Buenos Aires, Argentina · Biochemistry / INBA

The honeybee Apis mellifera is one of the main pollinators in agroecosystems, and, consequently, its colonies are exposed to agrochemicals and more fragmented and homogeneous habitats. As a social insect, this could lead to an impairment of colony health and population growth. Here, behavioral, molecular, and toxicological approaches were performed...

Soybean (Glycine max) is the world’s most widely grown seed legume. One of the most important pests that decrease seed quality and reduce yield of soybean crops is the southern green stink bug (Nezara viridula). Insect damage triggers accumulation of defensive compounds such as protease inhibitors (PIs), isoflavonoids and reactive oxygen species, w...

The honey bee Apis mellifera is a sentinel species of the pollinator community which is exposed to a wide variety of pesticides. In the last half-century, the pesticide most applied worldwide has been the herbicide glyphosate (GLY) used for weed control and with microbiocide effects. After its application in crops, the GLY residues have been detect...

Introduction Insect oviposition can enhance plant defenses and decrease plant quality in response to future feeding damage by hatched larvae. Induced resistance triggered by egg deposition and its negative effect on insect herbivore performance is known for several annual plants but has been much less studied in woody perennials, such as species of...

The potato tuberworm, Phthorimaea operculella Zeller, is an oligophagous pest feeding on crops mainly belonging to the family Solanaceae. It is one of the most destructive pests of potato worldwide and attacks foliage and tubers in the field and in storage. However, the lack of a high-quality reference genome has hindered the association of phenoty...

Background The southern green stinkbug (Nezara viridula) is a mayor pest of soybean. However, the mechanism underlying stinkbug resistance to soybean defenses is yet ignored. Although gut bacteria could play an essential role in tolerating plant defenses, most studies testing questions related to insect‐plant–bacteria interactions have been perform...

Over the last decades, Argentine and Brazilian farmers have adopted no‐tillage cultivation systems and multiple cropping, which have decreased the abundance of traditional pests, such as Nezara viridula, and favored the development of some stink bugs of secondary importance, like Dichelops furcatus, D. melacanthus and Euschistus heros. No‐till farm...

Lotus tenuis is a glycophytic forage legume (Fabaceae) used in feeding ruminants that can grow under salinity and waterlogging stresses. Plants obtained in controlled conditions were affected negatively in their growth by the effect of salt. Results from sequential extraction of plant cell wall polysaccharides and chemical characterization were rel...

The southern green stink bug, Nezara viridula is one of the primary soybean pests and causes significant economic losses around the world. In spite of the high proteases inhibitor (PI) levels, N. viridula can feed on developing seeds of field-grown soybean and reduce crop yields. Although the PI-induced responses have been extensively investigated...

The honeybee Apis mellifera is exposed to agricultural intensification, which leads to an improved reliance upon pesticide use and the reduction of floral diversity. In the present study, we assess the changes in the colony activity and the expression profile of genes involved in xenobiotic detoxification in larvae and adult honeybees from three ap...

BACKGROUND Recently, in temperate and neotropical regions of South America the generalist stink bug Dichelops furcatus (Hemiptera: Pentatomidae) became a new pest of corn (Zea mays) seedlings. Implementation of no‐tillage cultivation system left organic matter covering the soil, which shelters adults of stink bugs during winter. In spring, corn is...

The stink bug Nezara viridula is one of the most threatening pests for agriculture in North and South America, and its oral secretion may be responsible for the damage it causes in soybean (Glycine max) crop. The high level of injury to seeds caused by pentatomids is related to their feeding behavior, morphology of mouth parts, and saliva, though i...

Southern green stink bugs ( Nezara viridula L.) are one of the major pests in many soybean producing areas. They cause a decrease in yield and affect seed quality by reducing viability and vigor. Alterations have been reported in the oxidative response and in the secondary metabolites in different plant species due to insect damage. However, there...

Solar UV-B radiation enhances constitutive and inducible plant defenses against herbivore insects. Although inducible defenses in leaves damaged by lepidotperan larvae and other chewing insects are well known, almost nothing is noted for the response of reproductive organs in response to stink bug attack. Here we measured the induction of phytohorm...

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

This study demonstrates that soybean cultivars respond differentially to damage in a herbivore-specific manner, and trigger responses decreasing herbivore performance. Soybean crops are affected by a great number of insect herbivores, resulting in devastating yield losses. Secondary metabolites like proteinase inhibitors and phenolic compounds are...

After an insect herbivore has reached its host plant, contact cues from the leaf surface often determine host acceptance. We studied contact cues during oviposition behavior of a willow pest, the sawfly Nematus oligospilus (Hymenoptera: Tenthredinidae), a specialist feeder on Salix (Salicaceae) trees, and how it determines oviposition preference in...

As the main agricultural insect pollinator, the honey bee (Apis mellifera) is exposed to a number of agrochemicals, including glyphosate (GLY), the most widely used herbicide. Actually, GLY has been detected in honey and bee pollen baskets. However, its impact on the honey bee brood is poorly explored. Therefore, we assessed the effects of GLY on l...

Statistical procedure and R programming. (PDF)

Multiple post hoc comparison of head diameter among colonies. Statistics of Nemenyi test (d.f. = (15, 135)) to compare a pair of colonies in each rearing context. P-value was corrected with Bonferroni procedure. (PDF)

Simple effects reported in GLM model with significant interaction. Multiple post hoc comparison of weight among groups ([GLY] × colony term, F(6,108) = 16.33, P < 0.001, N = 120). Statistics of Tukey test to compare a pair of GLY concentrations in each colony. P-value was corrected with Bonferroni procedure (significant differences in bold). (PDF)

Effects of rearing context on gene expression within the epithelium gut. Measurement of the mean expression level of 16 genes has been performed in guts of 5-day-old dissected larvae sampled from three colonies (D, E and F) in both rearing contexts (in-hive or in vitro). A pool of 10 guts for each colony and context has been assessed (6 samples). A...

Gel electrophoresis of RT-PCR products of the target genes in each larval gut sample. Pool samples of 10 guts of 5-day-old larvae (reared in-hive or in vitro) sampled from three colonies (D, E and F) exposed to different concentrations of glyphosate (1.25–5.0 mg. of GLY per litre of food). One agarose gel was performed for each gene on all samples....

Changes in mean pH of food offered during the in vitro assessment. Five replicates per treatment have been measured daily throughout 5 days at incubator (34.5°C and 95% RH). GLMM followed by Tukey test to compare a pair of GLY concentrations. Treatments with different letters have significantly different means. (PDF)

Procedure conditions for each primer pair in the RT-PCR were optimized empirically to determine the linear range of amplification. (PDF)

Larval development during the growth period. Day by day photographic sequence of the expected development. Growth and feeding period corresponds to the first 144 hours after hatching. A) 0–17 h: First stadium (I) larva (circled in red). The instar (1.5 mm) has a translucent cuticle and a head that is hard to observe with the naked eye. B) 17–36 h:...

Effect of rearing context on growth. Larvae without adverse symptoms in larval development were sampled at 5-day of age from three colonies (D, E and F) in both rearing contexts (in-hive and in vitro). We measured in each larva their (a) head diameter (mm) and (b) weight (mg). The number of larvae measured was 10 for each rearing context per colony...

Row data of all measurements in the GLY assessment. (XLSX)

Comparison of gene expression levels assessed between rearing contexts. Statistics of Mann-Whitney U test to compare a pair of genes in each rearing context (in-hive or in vitro). (PDF)

Exposure conditions to glyphosate for the in vitro assessment. (PDF)

Simple effects reported in ATF models with significant interaction. Multiple post hoc comparison of survival curves ([GLY] × colony term, χ2 (15) = 211.29, P < 0.001) and successful moulting curves ([GLY] × colony term, χ2 (15) = 207.24, P < 0.001) among treatments in each colony. Statistics of Log-rank tests (d.f. = 1) to compare a pair of GLY con...

Simple effects for larvae reared in vitro without GLY reported in ATF models with significant interaction. Multiple post hoc comparison of control survival curves ([GLY] × colony term, χ2 (15) = 211.29, P < 0.001) and control successful moulting curves ([GLY] × colony term, χ2 (15) = 207.24, P < 0.001) among colonies. Statistics of Log-rank tests (...

Multiple post hoc comparison of head diameter among treatments. Statistics of Nemenyi test (d.f. = (15, 135)) to compare a pair of GLY concentrations or rearing contexts in each colony. P-value was corrected with Bonferroni procedure. (PDF)

Simple effects reported in GLM model with significant interaction. Multiple post hoc comparison of weight among groups ([GLY] × colony term, F(6,108) = 16.33, P < 0.001, N = 120). Statistics of Tukey test to compare a pair of colonies in each GLY concentration. P-value was corrected with Bonferroni procedure (significant differences in bold). (PDF)

The southern green stink bug (Nezara viridula) is a serious invasive pest in United States and South America that decreases the quantity and quality of soybean seeds. Plants respond to insect attack recognizing cell injury and oral secretions, triggering mitogen-activated protein kinases (MAPK) pathway and inducing defenses against herbivores. Our...

Solar UV-B radiation has been reported to enhance constitutive and inducible plant defenses against herbivore insects in many species. However, the induction of plant defenses depends on the phytohormone profile induced by the specific herbivore feeding guild. No study has shown the impact of soybean leaf chemical defenses induced by thrips herbivo...

The Southern green stinkbug (N. viridula) feeds on developing soybean seeds in spite of their strong defenses against herbivory, making this pest one of the most harmful to soybean crops. To test the hypothesis that midgut bacterial community allows stinkbugs to tolerate chemical defenses of soybean developing seeds, we identified and characterized...

Bacterial communities in the midgut of Nezara viridula associated to the insects hosts. (PDF)

Map of Argentina (a) and a zoom of central east Argentina (b) were 26 collecting events were performed during 2012–2014. Nezara viridula adults were handpicked from secondary hosts (light grey spots), Soybean (dark grey spots) or from under de bark of Eucalyptus trees (black spots). (PDF)

(a) Cysteine protease activity of N. viridula V1-V4 midgut ventricles. Statistical differences are denoted by different letters. (b) Distribution of ARISA detected bacteria among N. viridula V1-V4 midgut ventricles. Bacterial ITS fragments appear as blue peaks and LIZ 1200 weight standard fragments appear as yellow peaks. On a black square are 748...

Geographical placement of collecting sites. (PDF)

Bacteria isolated in this work and those used to build phylogenetic trees of Enterococcus sp. (PDF)

Bacteria isolated in this work and those used to build phylogenetic trees of Yokenella. (PDF)

The effect of early experiences on the brain during a sensitive period exerts a long-lasting influence on the mature individual. Despite behavioral and neural plasticity caused by early experiences having been reported in the honeybee Apis mellifera, the presence of a sensitive period in which associative experiences lead to pronounced modification...

Solar UV-B radiation has been reported to enhance plant defenses against herbivore insects in many species. However, the mechanism and traits involved in the UV-B mediated increment of plant resistance are unknown in crops species, such as soybean. Here we studied defense-related responses in undamaged and Anticarsia gemmatalis larvae-damaged leave...

Although it is well known that solar ultraviolet B (UV-B) radiation enhances plant defenses, there is less knowledge about traits that define insect resistance in field-grown soybean. Here we study the effects of solar UV-B radiation on: a) the induction of phenolic compounds and trypsin proteinase inhibitors (TPI) in soybean undamaged leaves or da...

Herbivory-induced changes in photosynthesis have been documented in many plant species, however the complexity of photosynthetic regulation and analysis has thwarted progress in understanding the mechanism involved, particularly those elicited by herbivore-specific elicitors. Here we analyzed the early photosynthetic gas-exchange responses in Nicot...

5DBQ: Crystal Structure of Insect Thioredoxin at 1.95 Angstroms https://www.ncbi.nlm.nih.gov/Structure/mmdb/mmdbsrv.cgi?uid=142250&dps=1

Isolation and characterization of a thioredoxin from Anticarsia gemmatalis cDNA https://www.ncbi.nlm.nih.gov/nuccore/983174930/

Industrialisation has elevated atmospheric levels of CO2 from original 280 ppm to current levels at 400 ppm, which is estimated to double by 2050. Although high atmospheric CO2 levels affect insect interactions with host plants, the impact of global change on plant defences in response to insect attack is not completely understood. Recent studies h...

Soybean (Glycine max), the most important legume crop in South and North America, is attacked by different insect pests that decrease crop yield. Plants have evolved sophisticated signaling networks that allow them to perceive and to cope with leaf herbivory. Herbivore attack alters levels of defensive phytohormones jasmonic acid (JA), salicylic ac...

Plant volatile organic compounds play a role in selection of host plants by herbivorous insects. Once the insect reaches the plant, contact cues determine host acceptance. Although the willow sawfly Nematus oligospilus (Hymenoptera: Tenthredinidae) can differentiate among willow genotypes, no knowledge is available on the cues used by this insect t...

Background: Southern green stink bugs (Nezara viridula) invade field-grown soybean crops, where they feed on developing seeds and inject phytotoxic saliva that causes yield reduction. Although leaf responses to herbivory are well studied, no information is available about the regulation of defenses in seeds. Results: This study demonstrated that...

The western corn rootworm (WCR, Diabrotica virgifera virgifera LeConte) is an important pest of corn. Annual crop rotation between corn and soybean disrupts the corn-dependent WCR lifecycle and is widely adopted to manage this pest. This strategy selected for rotation-resistant (RR) WCR with reduced ovipositional fidelity to corn. Previous studies...

Human industrialization has steadily raised atmospheric levels of CO 2 from 280 ppm prior to industrialization to current levels at 400 ppm and by 2050 are expected levels of 550 ppm. Climate change has important impacts on plant-insect interactions, and gaps in current understanding of plant responses to herbivory exist. Lately new empirical data...

Fluctuating temperatures terminate seed dormancy in many species, including Cynara cardunculus (L.) var. sylvestris. Termination of physiological dormancy requires low ratios of abscisic acid (ABA)/gibberellins (GA). In a previous paper we have shown that physiological responses to fluctuating temperatures comprise a reduction of abscisic acid (ABA...

Solar UV-B radiation (280–315 nm) has a significant influence on trophic relationships in natural and managed ecosystems, affecting plant-insect interactions. We explored the effects of ambient UV-B radiation on the levels of herbivory by stink bugs (Nezara viridula and Piezodorus guildinii) in field grow soybean crops. The experiments included two...

Insects are constantly adapting to human-driven landscape changes; however, the roles of their gut microbiota in these processes remain largely unknown. The western corn rootworm (WCR, Diabrotica virgifera virgifera LeConte) (Coleoptera: Chrysomelidae) is a major corn pest that has been controlled via annual rotation between corn (Zea mays) and non...

Sequences were screened for chimeras by the submitter using Mallard 1.02. ##Assembly-Data-START## Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##

Sequences were screened for chimeras by the submitter using Mallard 1.02. ##Assembly-Data-START## Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##

Sequences were screened for chimeras by the submitter using Mallard 1.02. ##Assembly-Data-START## Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##