The Possible overlap between Salinity and Mechanical Challenges in <I>Porteresia Coarctata</I>

Abstract

In nature, certain abiotic stresses constitutively acting on plants often go unrecognized. Mechanical stress is one of such stresses, which is manifested on a plant as low-spectrum pressure on the cell membrane due to wind, soil hindrance, gravity or wave current. Although all plants face constant threats from mechanical stress, some ecosystems are more prone to receive such stress. Mangrove vegetation is daily inundated by saline tidal waves that pose a serious threat to the soil binding force of forest undergrowth. Porteresia coarctata is a mangrove rice, which being wild, is avaluable germplasm for bioprospecting of genes and proteins that may confer salt-tolerance to domestic rice. However, P. coarctata is important from ecological point of view as its salt and mechanical stress tolerance is an integral part of the mangrove ecosystem. It is not possible to understand the basic biology of P. coarctata without an ecological perspective. The subterranean part of Porteresia provides a high anchorage and binds soil, thus stabilizing the mangrove vegetation. The root system architecture of Porteresia is unique, with a rhizome and rhizoid-like rootlets. The root system interacts with both salinity and mechanical threat directly, and thus it is important to understand the molecular ecophysiology of Porteresia root and rhizomes to understand the nature of overlap between salinity and mechanical stress in a mangrove ecosystem, which is still elusive.