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Effect of Zinc Deficiency on Growth, Phosphorus Concentration, and Phosphorus Toxicity of Wheat Plants
Author(s) -
Webb Michael J.,
Loneragan Jack F.
Publication year - 1988
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1988.03615995005200060032x
Subject(s) - shoot , toxicity , phosphorus , zinc , zinc deficiency (plant disorder) , chemistry , zoology , phosphate , phosphorus deficiency , dry matter , nutrient , horticulture , botany , biology , biochemistry , organic chemistry
In some previous experiments, Zn deficiency has enhanced P accumulation in old leaves to toxic concentrations by enhancing the rate of P absorption. This research was undertaken to examine the relationship of Zn deficiency to P accumulation and toxicity in young wheat plants ( Triticum aestivum L. ‘Gamenya’) grown in a complete nutrient solution with 1000 µ M phosphate and either with or without 2.5 µ M Zn. Mild Zn deficiency depressed shoot but enhanced root DM and this change was almost paralleled by P distribution. Severe Zn deficiency enhanced P concentration to 3 to 4% in old leaves and the marked necrotic symptoms were attributed to combined Zn deficiency and P toxicity. It depressed whole plant dry matter (DM) by 40% but P content by only 10%. It severely depressed DM distribution but enhanced P distribution to shoots thus doubling shoot P concentration. Short term and long term estimates indicate that mild Zn deficiency had only a transient effect in enhancing Pi absorption rate as severe Zn deficiency substantially depressed it. Thus, Zn deficiency enhanced P concentrations to toxic levels in old leaves through the cumulative effects of responses at three tiers of structural organization: (i) in the whole plant, it depressed DM more strongly than P content, (ii) between roots and shoots, it depressed that proportion of total DM which was present in shoots while increasing that of total P, (iii) within shoots, it concentrated P in old leaves by depressing new growth.