Mechanism of physiological tolerance to aluminium stress of legume cover crop species
2004
Utama, M.Z.H.((Universitas Tamansiswa, Padang (Indonesia). Fakultas Pertanian)) | Zen, Y.M. | Haryoko, W.
Aluminium ion (Al 3+) is toxic to plants at micro molar concentrations. Al toxicity has been known as major limiting factor for crop productivity on acid soil. The primary effect of Al toxicity is a rapid inhibition of root elongation due to detrimental effect on the targeting site of Al toxicity, the root apex. The research was aimed to study the physiological tolerance mechanism of legume cover crop species to Al stress. Two by two factors factorial experiment was conducted, each using a randomized complete design with three replications. First factor was 2 species of legume cover crops and second factor was level of aluminium on the growth media. The result showed that the tolerant species, Pueraria javanica had a better ability than the less tolerant Calopogonium ceurelium, to detoxify Al ion through a higher production of secreted organic acids to the growth media as the external mechanism and accumulation of the acid in the root as the internal mechanism. The organic acids reduce the Al activity through chelating process. Three most important chelating agents were citric, malice, and oxalic acid.
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