Performance of distinct crop pests reared on diets enriched with latex proteins from Calotropis procera: Role of laticifer proteins in plant defense
- 作者：Má ; rcio V. Ramos ; Cleverson D.T. Freitas ; Fern ; a Stanisç ; uaski ; Leonardo L.P. Macedo ; Maurí ; cio P. Sales ; Diego P. Sousa ; Cé ; lia R. Carlini
- 关键词：Anticarsia gemmatalis ; Calotropis procera ; Ceratitis capitata ; Dysdercus peruvianus ; Latex ; Spodoptera frugiperda
- 刊名：Plant Science
- 出版年：2007
- 期刊代码：88_01689452
- 类别：abs
- 出版时间：September 2007
- 卷：173
- 期：3
- 页码：349-357
- 文件大小：609 K
摘要
Latex-producing plants are widespread in different habitats. Usually these plants secrete an endogenous milk-like fluid in a network of laticifer cells in which sub-cellular organelles intensively synthesize proteins and secondary metabolites. The biological importance of latexes is still unclear and accumulated evidences of their physiological role are still limited. Here laticifer proteins (LP) from Calotropis procera were assayed for insecticidal action against different crop pests in attempt to give new insights for the biological role of latexes. Diets containing 4%LP affected survival (LD<sub>50sub> = 4.61%) and decreased weight gain (ED<sub>50sub> = 3.07%) of third instars Ceratitis capitata (Diptera: Tephritidae). Third instars Anticarsia gemmatalis (Lepidoptera: Noctuidae) fed on diets containing 0.1%(w/w) of LP showed reduced body mass while survival was reduced (LD<sub>50sub> = 0.48%) only for insects grown on 0.5%LP-containing diets. Nonetheless, 1%LP was ineffective against third instars Spodoptera frugiperda (Lepidoptera: Noctuidae). Diets containing 1%LP slightly diminished survival of Dysdercus peruvianus (Hemiptera: Pyrrhocoridae) nymphs while 2%LP was more effective with consistent reduction in bodyweight (ED<sub>50sub> = 1.4%) observed at the 14th day. Digestive enzymes of gut extracts of D. peruvianus were unable to breakdown LP. On the contrary, heat treated LP was capable of reducing by 50%proteolysis of gut extracts using BANA as substrate suggesting presence of inhibitory activity of cysteine proteinases. Adults of D. peruvianus were not affected when grown in diets containing 1%of LP. Laticifer proteins were shown to possess chitin-binding proteins and chitinolytic activity. Lectin activity was not detected. Occurrence of cysteine proteinase activity already reported in C. procera latex combined with the activities described here could explain, at least in part, the deleterious effects observed.