DIRECT DEFENSES IN DEVELOPING SEEDS OF SOYBEAN AGAINST GREEN STINK BUGS (Nezara viridula)

BARNETO, JÉSICA A.; SARDOY, PEDRO M.; ZAVALA, JORGE A.; PAGANO, EDUARDO A.

Potrero de los Funes, San Luis

Congreso; 47 Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2011

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

Insect  attack  increases  the  production  of  defenses,  which  are regulated by  the phytohormone  jasmonic acid  (JA). Southern green stink bug (Nezara viridula) is one of the main pests in soybean and affects both yield and seed quality. However, little is known about soybean  response  to  stink  bug  attack  on  developing  seeds. Developing seeds of soybean contain only lipoxygenases 1, 2, and 3, which probably regulates JA accumulation in these organs. Our aim was to determine the role of JA in the regulation of induced defenses, such as proteinase inhibitors (PI), when soybean seeds are  attacked by  stink bugs. We used  the Williams mutant BRM 926600  genotype,  without  expression  of  lox1,  2  and  3;  and Williams wt as a control. Four  treatments were applied on  seed pods:  i)  without  damage;  ii)  mechanical  damage;  iii)  damage produced  by  stink  bugs  attack  and;  iv)  application  of  methyl jasmonate (MeJA). The transcriptional expression of lox genes and pi were estimated by the RT-PCR reaction. Stink bug attack and mechanical damage induced gene expression of lox1, 2 and 3, and pi in control. Lox3 expression explained better the variation in the expression of  inhibitors  than  lox2 and 3. Although, no expression of either  lox1, 2, 3 or pi were found  in  the mutant BRM, application of MeJA  recuperated  the expression of  these genes, suggesting  that JA regulate PI en developing  seeds of  soybeans.