Greenbug resistance in wheat substitution lines, determined by their endogenous concentration of nonstructural carbohydrates and proteins

CASTRO AM; CLÚA AA; GIMÉNEZ DO; TOCHO E; TACALITI MS; WORLAND A; BOTTINI R; SNAPE JW

Wheat Production in Stressed Environments. Developments in Plant Breeding Vol. 12

Global Science Books

Año: 2007; p. 139 - 148

Tolerance to stress is one of the main purposes in breeding wheat production, and genes or chromosomal regions with positive effects on tolerance to biotic and abiotic stresses have been identified. This paper studied the response of bread wheat, Triticum aestivum (2n=6x=42) to greenbug attack or to exogenous application of stress-induced hormones ethylene (Et), jasmonic acid (JA), salicylic acid (SA) or ABA. Wheat intervarietal single chromosome substitution lines, with ?Chinese Spring? (CS, a greenbug susceptible line) as the recipient and a synthetic wheat (Triticum dicoccoides x T. tauschii, [Syn.]) as the donor, and both parents were used. One set of plants of each genotype were infested 72 h with 20 adult greenbugs per plant, another 4 sets were subjected to exogenous E, JA, SA or ABA and the remaining untreated plants were used as controls. Nine substitution lines showed tolerance to greenbug and to most of stress-induced hormones in terms of plant growth, protein content and aerial and root soluble carbohydrates (SC). However, stress-induced hormones were insufficient to mimic closely events associated with aphid feeding stress in terms of plant growth since growth of 3 substitution lines was significantly inhibited by greenbug and E and simultaneously showed tolerance to JA, SA and ABA. Conversely, one substitution line, greenbug tolerant, resulted susceptible to SA and ABA. Greenbug resistance genes have been previously mapped only on 4 chromosomes, but in this work it was possible to identify other chromosomes that showed positive effects in growth responses and protein levels, suggestting the complexity in the cascade of transductional signals that account for the crosstalk between tolerance to aphids and to stress-induced hormones.