Zinc translocation to wheat roots and its implications for a phosphorus/zinc interaction in wheat plants
Titel:
Zinc translocation to wheat roots and its implications for a phosphorus/zinc interaction in wheat plants
Auteur:
Webb, Michael J. Loneragan, Jack F.
Verschenen in:
Journal of plant nutrition
Paginering:
Jaargang 13 (1990) nr. 12 pagina's 1499-1512
Jaar:
1990-12
Inhoud:
Seven-day-old wheat plants (Triticum aestivum L. cv. Gamenya) were grown for a further 11 and 29 days using a split root technique such that 2.5 μM Zn was added to both (Zn++), one (Zn+0), or neither (Zn00) of paired half-root systems in an otherwise complete nutrient solution. When compared with Zn++ plants, the Zn+0 treatment had no effect on dry matter (DM) of wheat plants or plant parts. Indeed, in all respects, Zn+0 plants appeared identical to Zn++ plants. By contrast, at final harvest, Zn00 plants had symptoms of severe Zn deficiency and P toxicity, and depressed whole plant DM. The Zn+0 treatment was used to calculate translocation rates of Zn from one half-root system to the other while all three treatments were used to study the effect of Zn supply on P accumulation. Zinc translocation from day 18 (D18) to D36 from the half-root system supplied with Zn (Ra) to the half-root system not supplied with Zn (Rb) was 1.0 to 1.5 mg Zn/kg DM RB/day. This rate of translocation could maintain a concentration of 9 to 14 mg Zn/kg DM in Rb if the growth rate of Rb remained unchanged. When compared with Zn++ plants, Zn+o plants had slightly depressed P concentration in some shoot parts due to a small depression in P absorption rate by the root not supplied with Zn. By contrast, at final harvest, Znoo plants had markedly enhanced P concentrations in shoots and shoot parts. Between the two harvests, Zn00 had depressed the absorption rate of P. That Zn+0 plants behaved like Zn++ plants suggests that the enhanced P concentration in Zn deficient (Zn00) plants was mediated primarily through an effect of Zn in the shoots rather than in the roots.
Tijdschrift beschrijving