Expression of soybean proteinase inhibitors in transgenic sugarcane plants: effects on natural defense against Diatraea saccharalis

• Published in: Plant physiology and biochemistry 2003-08, Vol.41 (8), p.761-766
• Main Authors: Falco, Maria Cristina, Silva-Filho, Marcio C.
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; DEFENCE MECHANISMS; DIATRAEA SACCHARALIS; Fundamental and applied biological sciences. Psychology; Genetics and breeding of economic plants; GLYCINE MAX; HOST PARASITE RELATIONS; INHIBIDORES DE PROTEINASAS; INHIBITEUR DE PROTÉINASES; Insect resistance; MECANISMOS DE DEFENSA; MÉCANISME DE DÉFENSE; Pest animals; PEST RESISTANCE; PROTEINASE INHIBITORS; RELACIONES HUÉSPED PARÁSITO; RELATION HÔTE PARASITE; RESISTENCIA A LAS PLAGAS; RÉSISTANCE AUX ORGANISMES NUISIBLES; SACCHARUM OFFICINARUM; Soybean proteinase inhibitors; Sugarcane; Varietal selection. Specialized plant breeding, plant breeding aims
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/S0981-9428(03)00100-1

The introduction and expression of proteinase inhibitor encoding genes into sugarcane ( Saccharum officinarum L.) genome is an interesting strategy for conferring partial resistance to the sugarcane borer Diatraea saccharalis (Lepidoptera: Crambidae), the major insect pest of sugarcane in Brazil. To investigate the role of soybean ( Glycine max L.) Kunitz trypsin inhibitor (SKTI) and soybean Bowman–Birk inhibitor (SBBI) in the control of D. saccharalis, the cDNAs encoding these proteinase inhibitors were placed under the control of the maize ubiquitin promoter ( Ubi-1), and introduced into sugarcane callus using particle bombardment. Putative transgenic plants were initially identified after regeneration from callus growing in the presence of 30 mg l –1 geneticin, while molecular characterization of transgenic plants revealed that both genes were incorporated into the sugarcane genome and expressed. We also carried out insect feeding trials using D. saccharalis neonate larvae and leaf tissue excised from propagated transgenic and untransformed plants, and found that the growth of larvae feeding on leaf tissue from transgenic plants containing BBI and Kunitz inhibitors was significantly retarded as compared to larvae fed on leaf tissue from untransformed plants. In greenhouse trials with transgenic sugarcane plants infested with D. saccharalis neonates, we found that these plants still presented the ‘dead heart’ symptom typically observed in susceptible plants in the field, suggesting that the retardation of the growth of D. saccharalis observed in the laboratory-based feeding trials was not sufficient to prevent this type of damage.