Jorge A Zavala

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

PhD

About

141
Publications
10,050
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3,713
Citations
Additional affiliations
January 2012 - present
Universidad de Buenos Aires
January 2008 - December 2012
May 2007 - present
National Scientific and Technical Research Council
Position
  • Investigador Independiente

Publications

Publications (141)
Article
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 perfo...
Article
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...
Article
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...
Article
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...
Article
Full-text available
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...
Article
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...
Article
Full-text available
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...
Article
Full-text available
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...
Article
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...
Article
Full-text available
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...
Article
Full-text available
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...
Article
Full-text available
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...
Data
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)
Data
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)
Data
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...
Data
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....
Data
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)
Data
Procedure conditions for each primer pair in the RT-PCR were optimized empirically to determine the linear range of amplification. (PDF)
Data
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:...
Data
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...
Data
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)
Data
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...
Data
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 (...
Data
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)
Data
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)
Article
Full-text available
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...
Article
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...
Article
Full-text available
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...
Data
Bacterial communities in the midgut of Nezara viridula associated to the insects hosts. (PDF)
Data
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)
Data
(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...
Data
Geographical placement of collecting sites. (PDF)
Data
Bacteria isolated in this work and those used to build phylogenetic trees of Enterococcus sp. (PDF)
Data
Bacteria isolated in this work and those used to build phylogenetic trees of Yokenella. (PDF)
Article
Full-text available
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...
Article
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...
Article
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...
Article
Full-text available
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...
Research
Full-text available
5DBQ: Crystal Structure of Insect Thioredoxin at 1.95 Angstroms https://www.ncbi.nlm.nih.gov/Structure/mmdb/mmdbsrv.cgi?uid=142250&dps=1
Research
Full-text available
Isolation and characterization of a thioredoxin from Anticarsia gemmatalis cDNA https://www.ncbi.nlm.nih.gov/nuccore/983174930/
Article
Full-text available
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...
Chapter
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...
Article
Full-text available
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...
Article
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...
Article
Full-text available
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...
Chapter
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...
Article
Full-text available
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...
Article
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...
Article
Full-text available
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...