Paper Details

Lead phytotoxicity on some plant growth parameters and proline accumulation in mycorrhizal tomato (Lycopersicon esculentum L.)

Setareh Amanifar, Nasser Aliasgharzad, Mahmoud Toorchi, Mehdi Zarei

DOI: https://dx.doi.org/10.12692/ijb/4.10.80-88

Int. J. Biosci. 4(10), 80-88. May, 2014. (PDF)

Abstract:

Interaction between mycorrhizal fungi and plants under heavy metal polluted condition can alleviate stress condition for plants. This may be due to the better nutrition in mycorrhizal plants than non-mycorrhizal ones. In this study we assayed the chlorophyll content, leaf area, proline concentration, phosphate and lead contents, mycorrhizal dependency and efficiency of photosystem II (PS II) of plants. Tomato plants were inoculated either with Glomus intraradices or Glomus mosseae. Control plants were left un-inoculated as non-mycorrhizal treatments. Four levels of Pb2+, including 0, 50, 100 and 150 mg L-1 were used as Pb(NO3)2. Increasing Pb2+ concentration decreased leaf area, efficiency of photosystem II, chlorophyll content, root colonization rate, shoot and root phosphate content significantly. Also, increasing lead increased root lead content and root to shoot ratio of Pb2+ concentration. Raising the lead concentration has no significant effect on shoot lead content. Mycorrhizal dependency increased with increasing the lead concentration. Generally, 150 mg L-1 of lead treated mycorrhizal plants had better growth in comparison to non-mycorrhizal plants. It can be concluded that mycorrhizal inoculation increases tomato plant tolerance to lead which may be related to either modified prolin metabolism (specially in Glomus intraradices inoculated plants), better phosphorus nutrition or lead sequestration in mycorrhizal roots.