An Anomaly in Potassium Accumulation by Barley Roots: II. Effect of Calcium Concentration and Rubidium-86 Labeling.

نویسنده

  • A J Hiatt
چکیده

When excised barley roots were incubated in 0.01 to 0.1 mm KCl solutions containing 0.2 mm CaSO(4), there was a peak in the K(+) accumulation against concentration curve at 0.02 to 0.04 mm KCl. The peak in the K(+) accumulation curve was shifted to lower K(+) concentrations when Ca(2+) concentration was decreased and to higher K(+) concentrations when Ca(2+) concentration was increased. Increasing Ca(2+) concentration in the treatment solution was observed to be stimulatory, inhibitory, or neutral depending on the K(+) concentration.When (86)Rb was used as an isotopic tracer for K(+), accumulation of K(+) was grossly overestimated, and the apparent K(+) accumulation curve, as estimated with (86)Rb-labeled K(+), was hyperbolic over the concentration range of 0.01 to 0.1 mm. It was concluded that (86)Rb is a poor tracer for K(+) over the concentration range of 0.01 to 0.1 mm. Accumulation of Rb(+) in the presence of K(+) was accurately measured by (86)Rb.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Accumulation of rubidium-86 by the rabbit lens.

Rabbit lenses incubated in vitro in potassium-free Tyrode's solution for 4 hours accinnulated trace amounts of Rb-86 to a concentration averaging 18 times that of the incubation medium. The uptake of Rb-86 was temperature dependent and required calcium. In the presence of glucose it was inhibited by iodoacetate, ouabain, or digoxin, but not by dinitrophenol, fluoroacetate, or anaerobiosis. The ...

متن کامل

Influence of minerals on valerenic acid accumulation in hairy root cultures of Valeriana officinalis L. . Mohammad Reza Dini Torkamani1* and Afsaneh Samadi2

The roots and rhizomes of Valeriana (Valerianaofficinalis L.) are rich with valuable metabolites such as valerenic acid and valepotriates are used as mild sedatives. The aim of the present study was to investigatethe effect of four levels of calcium and potassium compounds (half, full, 2 and 4-fold) of normal Murashige and Skoog (MS) media including KI and CaCl2on ValerianaofficinalisL. hairy r...

متن کامل

Effects of Calcium, Indoleacetic Acid & Distance From Stem Apex on Potassium & Rubidium Absorption by Excised Segments of Etiolated Pea Epicotyl.

The enhancing effect of Ca on K uptake by excised roots has been known for some time (25) and has been referred to as the Viets effect; however, whether or not such an enhancement occurs in stem tissue has not been established. Indoleacetic acid (IAA) may enhance Rb uptake by stem segments (11) and this effect in Jerusalem artichoke tuber tissue has been attributed to an increase in capacity of...

متن کامل

Effect of Calcium and Cadmium on Growth and Accumulation of Cadmium, Calcium, Potassium and Sodium in Maize Seedlings

we examined cadmium (0.1 mmol/l) toxicity and effect of different calcium concentrations (0.1, 1.0, and 10.0 mmol/l) on the growth of organs (root, mesocotyl and coleoptile) of 4-day-old maize seedlings in hydroponic cultures. The influence of both metals on distribution of cadmium, calcium, potassium and sodium in the organs of maize seedlings was also studied. Calcium at a concentration of 1....

متن کامل

Distribution of rubidium-86 accumulated in the rabbit lens.

he in vitro accumulation of rubidium86 has provided a simple and convenient method for evaluating cation transport by the rabbit lens. The accumulation of rubidium occurred against a concentration gradient, was temperature dependent, demonstrated saturation kinetics, and was inhibited "competitively" by potassium. The accumulation was also inhibited by ouabain in concentrations as low as 10~ M....

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • Plant physiology

دوره 45 4  شماره 

صفحات  -

تاریخ انتشار 1970