BASIL IONIC RESPONSES TO SEAWATER STRESS AND THE IDENTIFICATION OF GLAND SALT SECRETION Authors: J. F. Ninga, L. H. Cuib, S. H. Yanga, S. Y. Aia, M.J. Lia, L. L. Suna, Y. Chena, R.H. Wanga, Z. B. Zenga Journal: Journal of Animal and Plant Sciences (JAPS) ISSN: 1018-7081 (Print), 2309-8694 (Online) Volume: 25 Issue: 1 Pages: 131-138 Year: 2015 DOI: NA URL: https://doi.org/NA Publisher: Pakistan Agricultural Scientists Forum Abstract:

Basil (Ocimum Basilicum) seedlings were subjected to 0,5%,10%,20% and 40% seawater for 10 days under shade house conditions. Increasing seawater concentration led to considerable reduction in plant dry matter accumulation. However, root growth was not affected till treated with 40% seawater. Accumulations of Na+ and Cl- were correlated with decline of Ca2+ and K+ in stems, roots or both. Contents of Ca2+ and K+ in leaves increased or remained relatively unchanged with increasing salt levels. In salinity-stressed plants, Na+ were partitioned mainly in roots and more than 50% of the K+ and Ca2+ were stored in leaves. Higher K+/Na+ and Ca2+/Na+ ratios in leaves rather than in roots and stems were observed in Basil plants. Scanning electron microscopy coupled with X-ray microanalysis showed that Basil leaf gland secretions contained Na+ and Ca2+. The Na+ secretion increased while Ca2+ secretion decreased with the increasing seawater concentration. These results suggested that Basil salt tolerance is associated with the compartmentation of Na+ in roots and the balance of K+, Na+ and Ca2+ in leaves as well as the salt secretion by the leaf glands.

Keywords: Ocimumbasilicum L.; Basil; Ion balance; Salt secretion; Seawater stress; X-ray microanalysis