Direct and indirect resistance of sugarcane to Diatraea saccharalis induced by jasmonic acid.

Treating plants with synthetic jasmonic acid (JA) induces a defensive response similar to herbivore attack, and is a potential strategy for integrated pest management. Despite the importance of sugarcane, its JA-induced defences have not yet been studied. We investigated the effects of JA treatment on the direct and indirect resistance of sugarcane to the key-pest and specialist herbivore Diatraea saccharalis and the generalist Spodoptera frugiperda. Indirect defences were examined by testing the attraction of Cotesia flavipes, a sugarcane-borer parasitoid, to JA-induced volatile. The results showed that JA-treated sugarcane did not affect the weight gain of the two larvae. However, in dual-choice assays, both species preferred to feed on mock rather than JA-treated plants. Leaf colorimetric analyses showed that visual cues are unlikely to be involved in larval preference, whereas results from olfactometric assays revealed that D. saccharalis preferred JA-induced over mock plant volatiles. After 48 h of treatment, JA-treated plants emitted a volatile blend attractive to C. flavipes, comprised mainly of sesquiterpenes. However, the parasitoid did not discriminate JA-treated from host-damaged plant volatiles. When the wasps were given a choice between JA-treated and JA-treated + host-damaged plants, they preferred the latter, which emitted a more complex blend, suggesting that JA treatment likely does not hamper host-finding. We concluded that JA induces the emission of volatiles that are attractive to the sugarcane borer parasitoid, as well as an antixenosis type of resistance in sugarcane against the two pests, although neither volatiles nor visual cues alone are involved in the underlying mechanism.

[Left heart catheterization by the transseptal route]. / Cateterismo cardíaco esquerdo por via transeptal.

PURPOSE: To analyse the transseptal catheterization technique, its indications and possible complications. METHODS: The transseptal catheterization has been undertaken in 233 patients, 202 children (aged 0.1 to 16 years) with congenital heart disease and 31 adults (aged 37 to 73 years) submitted to mitral valvuloplasty. The Mullins technique was employed to access left heart chambers. RESULTS: In the pediatric group, the indications for transseptal catheterization were coarctation of the aorta and valvular or subvalvular aortic stenosis. By this technique, multiple diagnostic analysis and therapeutic procedures, such as blade atrioseptostomy and mitral valvuloplasty, became available. Among the complications in the 2 groups, pericardial perforation was the most frequent, depending on the laboratory practice with this technique. CONCLUSION: The transseptal cardiac catheterization is a safe and effective technique to investigate hemodynamic data in several congenital heart diseases and is essential to many therapeutic procedures. The technique has a low incidence of complications when employed by experienced teams.