CHANGES IN HULL CELL WALLS STRUCTURE PRODUCED BY ATTACK OF STINKBUG NEZARA VIRIDULA ON DEVELOPING SOYBEAN SEEDS

ZAVALA J. A; CIANCIA, M.; ARIAS F

Cordoba

Congreso; XXXII Reunión Argentina de Fisiología Vegetal (RAFV) y XVI Congreso Latinoamericano de Fisiología Vegetal; 2018

Nezara viridula is one the most important pests in soybean crops. Soybean responds to stinkbug attack inducing defenses regulated by salicylic acid. Cell walls can be an effective barrier against piercing-sucking insects. In mature soybean carbohydrates make up 35% of (SB) seeds. No detailed study on hull polysaccharides in the immature stage, when Nezara attack takes place. The aim of this work was to determine if stinkbug damage produces changes in cell wall polysaccharides.Hull cell wall polysaccharides from seeds of a commercial cultivar were studied. One untreated (CTR) lot and two different treatments were prepared, during R5 stage: (1) stinkbug damaged ? insects were placed on pods and enclosed with a fine mesh bag, during 15 days (BD); (2) pods sprayed with 1.5 mM of salicylic acid every 4 days, during 15 days (TSA), This were collected in R6 stage. Sequential extraction with water, 0.05 M CDTA pH 6, 0.05 M Na2CO3, 1M KOH, and 4M KOH was carried out. Analyses showed major differences between treatments in structure of mannans, and non-esterified homogalacturonans (HG) and in the ratio RGI:methyl-esterified HG. These results show that stinkbug attack produces measurable changes in hull cell wall structure from Glicine max.