Plants respond to herbivorous attack through a defence system that includes structural barriers, release of toxic chemicals, and attraction of natural enemies of the target pests, etc. In this study, plants of Bougainvillea glabra Choisy (Nyctaginaceae) were artificially infested with the obligate phloem-feeding insect pest Phenacoccus peruvianus Granara de Willink (Hemiptera: Pseudococcidae) and compared with control uninfested plants. Leaf samples were collected at 2, 6, 12, 24, 48, 96 and 144Â h after infestation to monitor the plant response. Proline (Pro), malondialdehyde (MDA), chlorophyll (Chla, Chlb, and Chla+b), and total carotenoid (Car) contents, as well as the activities of catalase (CAT) and phenylalanine ammonia-lyase (PAL) antioxidant enzymes, were measured at each sampling time to better understand the mechanism of plant defences. Proline content was the highest at 2Â h after infestation and remained high throughout the experiment, while MDA content differed significantly only at 12Â h after infestation. The value of chlorophyll was higher in the control plants, indicating that insect attack seriously compromised the photosynthetic activity of infected plants. Enzymatic activities showed significant increases, CAT of about 50% after 24Â h and PAL of about 43% after 6Â h. This study will be useful for understanding Bougainvillea plant defence against mealybugs and for showing that this ornamental species is able to activate enzymatic and molecular mechanisms in response to insect attack.
|Titolo:||Induced responses of Bougainvillea glabra Choisy (Nyctaginaceae) against Phenacoccus peruvianus Granara de Willink (Hemiptera: Pseudococcidae) attack: preliminary results|
|Data di pubblicazione:||2018|
|Appare nelle tipologie:||1.1 Articolo in rivista|