Protective role of boiling stable antioxidant enzymes in invasive alien species of Lantana exposed to natural abiotic stress like conditions

Abstract

Lantana camara is an annual invasive weed of Verbenaceae family, which is native to tropical America while wide spread in North America, Africa, Australia and India. It tolerates a wide variety of abiotic conditions in the natural habitat. In the present study the abiotic stress-induced changes on reactive oxygen species (ROS) contents such as hydrogen peroxide (H₂O₂) and ROS scavenging boiling stable antioxidant proteins such as glutathione S-transferase (GST), glutathione reductase (GR), monodehydroascorbatereductase (MDAR), thioredoxin-reductase (TRx) and protein disulphide isomerise (PDI) were studied in three different most prevalent varieties of Lantana. The experiments were conducted from December-2013 to June- 2014. The study followed a random sampling method so that no bias is introduced. Three sites at random were selected and plant samples at reproductive stage (leaves and flowers) were collected from plants and pooled together for further analysis. Indices of oxidative stress, H₂O₂ level either increased or unchanged under low and high temperature conditions in a genotype and tissue dependent manner were determined. In Lantana the coordinated increase in the activities of various boiling stable antioxidant enzymes like GR, GST, PDI, TRx and MDAR was observed under adverse abiotic conditions in a genotype, and tissue specific manner. It was postulated that pink genotype may have more efficient mechanism to scavenge ROS species as shown by exorbitant increase in boiling stable antioxidant activities (BsGST, BsPDI, BsMDAR). Based on results it can be inferred that plants which are more invasive may have more biochemical capacity to perform biological antioxidative reactions to combat abiotic stress-induced oxidative stress. Overall, the present study findings can be used to control the invasiveness of invasive alien plants worldwide.