Plant-insect interactions in soybean crops: Plant responses to stink Bugs (Nezara viridula) attack.

ZAVALA, J. A.; BARNETO, J.; BARRIGA, L.; PAGANO, E.A.

Colonia del Sacramento

Simposio; 1st Latin American Meeting of Chemical Ecology,; 2010

Latin American Association of Chemical Ecology

Soybean (Glycine max), the world’s most widely grown seed legume, can be attacked byGlycine max), the world’s most widely grown seed legume, can be attacked by Nezara viridula that decreases crops yields and quality of seeds. Soybeans have constitutive and inducible defenses against insect attack, such as proteinase inhibitors (PI) and isofl avonoids, which decreases amino acids assimilation in the gut and, in turn, insect performance. Th ese chemical defenses are regulated by the hormones jasmonic acid (JA) and ethylene (ET). While ET in soybean seeds is regulated by the expression of 1-aminocyclopropane- 1-carboxylate synthase (acc-s), JA is regulated by lipoxygenase 1, 2 and 3 (lox1, lox2 and lox3). However, insects can suppresses plant defenses through manipulating the defense hormones ET and JA. To test this hypothesis developing soybean seeds were either i) attacked by adult stink bugs collected from the fi eld, or ii) treated with MeJA, or iii) mechanically damaged, or iv) no damaged (control). Plant material was collected 24h and 72h aft er treatments, and fl ash frozen in liquid nitrogen. While only insect attack and mechanical damage increased acc-s expression, the highest induced expression of lox1, 2 defense hormones ET and JA. To test this hypothesis developing soybean seeds were either i) attacked by adult stink bugs collected from the fi eld, or ii) treated with MeJA, or iii) mechanically damaged, or iv) no damaged (control). Plant material was collected 24h and 72h aft er treatments, and fl ash frozen in liquid nitrogen. While only insect attack and mechanical damage increased acc-s expression, the highest induced expression of lox1, 2 lox2 and lox3). However, insects can suppresses plant defenses through manipulating the defense hormones ET and JA. To test this hypothesis developing soybean seeds were either i) attacked by adult stink bugs collected from the fi eld, or ii) treated with MeJA, or iii) mechanically damaged, or iv) no damaged (control). Plant material was collected 24h and 72h aft er treatments, and fl ash frozen in liquid nitrogen. While only insect attack and mechanical damage increased acc-s expression, the highest induced expression of lox1, 2 defense hormones ET and JA. To test this hypothesis developing soybean seeds were either i) attacked by adult stink bugs collected from the fi eld, or ii) treated with MeJA, or iii) mechanically damaged, or iv) no damaged (control). Plant material was collected 24h and 72h aft er treatments, and fl ash frozen in liquid nitrogen. While only insect attack and mechanical damage increased acc-s expression, the highest induced expression of lox1, 2 and inducible defenses against insect attack, such as proteinase inhibitors (PI) and isofl avonoids, which decreases amino acids assimilation in the gut and, in turn, insect performance. Th ese chemical defenses are regulated by the hormones jasmonic acid (JA) and ethylene (ET). While ET in soybean seeds is regulated by the expression of 1-aminocyclopropane- 1-carboxylate synthase (acc-s), JA is regulated by lipoxygenase 1, 2 and 3 (lox1, lox2 and lox3). However, insects can suppresses plant defenses through manipulating the defense hormones ET and JA. To test this hypothesis developing soybean seeds were either i) attacked by adult stink bugs collected from the fi eld, or ii) treated with MeJA, or iii) mechanically damaged, or iv) no damaged (control). Plant material was collected 24h and 72h aft er treatments, and fl ash frozen in liquid nitrogen. While only insect attack and mechanical damage increased acc-s expression, the highest induced expression of lox1, 2 defense hormones ET and JA. To test this hypothesis developing soybean seeds were either i) attacked by adult stink bugs collected from the fi eld, or ii) treated with MeJA, or iii) mechanically damaged, or iv) no damaged (control). Plant material was collected 24h and 72h aft er treatments, and fl ash frozen in liquid nitrogen. While only insect attack and mechanical damage increased acc-s expression, the highest induced expression of lox1, 2 lox2 and lox3). However, insects can suppresses plant defenses through manipulating the defense hormones ET and JA. To test this hypothesis developing soybean seeds were either i) attacked by adult stink bugs collected from the fi eld, or ii) treated with MeJA, or iii) mechanically damaged, or iv) no damaged (control). Plant material was collected 24h and 72h aft er treatments, and fl ash frozen in liquid nitrogen. While only insect attack and mechanical damage increased acc-s expression, the highest induced expression of lox1, 2 defense hormones ET and JA. To test this hypothesis developing soybean seeds were either i) attacked by adult stink bugs collected from the fi eld, or ii) treated with MeJA, or iii) mechanically damaged, or iv) no damaged (control). Plant material was collected 24h and 72h aft er treatments, and fl ash frozen in liquid nitrogen. While only insect attack and mechanical damage increased acc-s expression, the highest induced expression of lox1, 2 that decreases crops yields and quality of seeds. Soybeans have constitutive and inducible defenses against insect attack, such as proteinase inhibitors (PI) and isofl avonoids, which decreases amino acids assimilation in the gut and, in turn, insect performance. Th ese chemical defenses are regulated by the hormones jasmonic acid (JA) and ethylene (ET). While ET in soybean seeds is regulated by the expression of 1-aminocyclopropane- 1-carboxylate synthase (acc-s), JA is regulated by lipoxygenase 1, 2 and 3 (lox1, lox2 and lox3). However, insects can suppresses plant defenses through manipulating the defense hormones ET and JA. To test this hypothesis developing soybean seeds were either i) attacked by adult stink bugs collected from the fi eld, or ii) treated with MeJA, or iii) mechanically damaged, or iv) no damaged (control). Plant material was collected 24h and 72h aft er treatments, and fl ash frozen in liquid nitrogen. While only insect attack and mechanical damage increased acc-s expression, the highest induced expression of lox1, 2 defense hormones ET and JA. To test this hypothesis developing soybean seeds were either i) attacked by adult stink bugs collected from the fi eld, or ii) treated with MeJA, or iii) mechanically damaged, or iv) no damaged (control). Plant material was collected 24h and 72h aft er treatments, and fl ash frozen in liquid nitrogen. While only insect attack and mechanical damage increased acc-s expression, the highest induced expression of lox1, 2 lox2 and lox3). However, insects can suppresses plant defenses through manipulating the defense hormones ET and JA. To test this hypothesis developing soybean seeds were either i) attacked by adult stink bugs collected from the fi eld, or ii) treated with MeJA, or iii) mechanically damaged, or iv) no damaged (control). Plant material was collected 24h and 72h aft er treatments, and fl ash frozen in liquid nitrogen. While only insect attack and mechanical damage increased acc-s expression, the highest induced expression of lox1, 2 defense hormones ET and JA. To test this hypothesis developing soybean seeds were either i) attacked by adult stink bugs collected from the fi eld, or ii) treated with MeJA, or iii) mechanically damaged, or iv) no damaged (control). Plant material was collected 24h and 72h aft er treatments, and fl ash frozen in liquid nitrogen. While only insect attack and mechanical damage increased acc-s expression, the highest induced expression of lox1, 2 acc-s), JA is regulated by lipoxygenase 1, 2 and 3 (lox1, lox2 and lox3). However, insects can suppresses plant defenses through manipulating the defense hormones ET and JA. To test this hypothesis developing soybean seeds were either i) attacked by adult stink bugs collected from the fi eld, or ii) treated with MeJA, or iii) mechanically damaged, or iv) no damaged (control). Plant material was collected 24h and 72h aft er treatments, and fl ash frozen in liquid nitrogen. While only insect attack and mechanical damage increased acc-s expression, the highest induced expression of lox1, 2 defense hormones ET and JA. To test this hypothesis developing soybean seeds were either i) attacked by adult stink bugs collected from the fi eld, or ii) treated with MeJA, or iii) mechanically damaged, or iv) no damaged (control). Plant material was collected 24h and 72h aft er treatments, and fl ash frozen in liquid nitrogen. While only insect attack and mechanical damage increased acc-s expression, the highest induced expression of lox1, 2 and lox3). However, insects can suppresses plant defenses through manipulating the defense hormones ET and JA. To test this hypothesis developing soybean seeds were either i) attacked by adult stink bugs collected from the fi eld, or ii) treated with MeJA, or iii) mechanically damaged, or iv) no damaged (control). Plant material was collected 24h and 72h aft er treatments, and fl ash frozen in liquid nitrogen. While only insect attack and mechanical damage increased acc-s expression, the highest induced expression of lox1, 2acc-s expression, the highest induced expression of lox1, 2 and 3 was found aft er insect attack. Furthermore, insect attack induced the highest levels of isfl avonoids (daidzin y genistin) in developing seeds. However, although mechanical damage and JA increased pi expression, insect attack did not increase pi transcript and activity levels. Our results suggest, although N. viridula attack suppresses PI elicitation, plants still respond to insect damage increasing isofl avoind production, which is a good defense against these insects. plants still respond to insect damage increasing isofl avoind production, which is a good defense against these insects. activity levels. Our results suggest, although N. viridula attack suppresses PI elicitation, plants still respond to insect damage increasing isofl avoind production, which is a good defense against these insects. plants still respond to insect damage increasing isofl avoind production, which is a good defense against these insects. of isfl avonoids (daidzin y genistin) in developing seeds. However, although mechanical damage and JA increased pi expression, insect attack did not increase pi transcript and activity levels. Our results suggest, although N. viridula attack suppresses PI elicitation, plants still respond to insect damage increasing isofl avoind production, which is a good defense against these insects. plants still respond to insect damage increasing isofl avoind production, which is a good defense against these insects. activity levels. Our results suggest, although N. viridula attack suppresses PI elicitation, plants still respond to insect damage increasing isofl avoind production, which is a good defense against these insects. plants still respond to insect damage increasing isofl avoind production, which is a good defense against these insects. 3 was found aft er insect attack. Furthermore, insect attack induced the highest levels of isfl avonoids (daidzin y genistin) in developing seeds. However, although mechanical damage and JA increased pi expression, insect attack did not increase pi transcript and activity levels. Our results suggest, although N. viridula attack suppresses PI elicitation, plants still respond to insect damage increasing isofl avoind production, which is a good defense against these insects. plants still respond to insect damage increasing isofl avoind production, which is a good defense against these insects. activity levels. Our results suggest, although N. viridula attack suppresses PI elicitation, plants still respond to insect damage increasing isofl avoind production, which is a good defense against these insects. plants still respond to insect damage increasing isofl avoind production, which is a good defense against these insects. pi expression, insect attack did not increase pi transcript and activity levels. Our results suggest, although N. viridula attack suppresses PI elicitation, plants still respond to insect damage increasing isofl avoind production, which is a good defense against these insects. plants still respond to insect damage increasing isofl avoind production, which is a good defense against these insects. N. viridula attack suppresses PI elicitation, plants still respond to insect damage increasing isofl avoind production, which is a good defense against these insects.