The expression pattern of an acid phosphatase from Arabidopsis thaliana under phosphate starvation condition.

Esfahani, Kasra^1,2; Lohrasbi, Tahmineh¹; Shobbar, Zahra¹ and Malboobi, Mohammad Ali¹.

1. National Research Center for Genetic Engineering and Biotechnology,

    P.O. Box: 14155-6343, Tehran, Iran.

2. Agriculture Faculty of Tehran University, Karaj, Iran.

Despite of the presence of insoluble phosphorous compounds in the soil, plants are usually faced with low amounts of absorbable phosphate causing decreased growth rate and yield. Some plants, such as Brassicaceae plants, synthesize enzymes known as acid phosphatase that release soluble phosphate from its insoluble compounds inside or outside of the cells.

A sequence encoding an acid phosphatase in Arabidobsis thaliana was amplified by RT-PCR using primers designed based on conserved sequences of plant acid phosphatases genes. The effects of  some stresses like phosphate deficiency, sulfate deficiency, nitrate deficiency, 2 hours cold condition, a day cold condition, presence of chitinn in culture as a fangi contamination and some others on expression of this gene in plant root were studied by comparative-quantitative RT-PCR. It was shown that not only phosphate deficiency, but also 24 hours cold stress, caused increase in the expression of this gene in root. Two hours cold stress, sulfur deficiency and high salt stresses had no remarkable effect on the expression of this gene in root, however nitrogen starvation reduced the level of expression. Although the salt stress had no effect on expression in root, but it increased the expression of acid phosphatase gene in shoot of Arabidobsis plants. It was also revealed that the expression of this gene was increased accumulatively when the phosphate starvation continued. The expression was increased gradually by the fifth day when remained almost the same until fourteenth day of phosphate starvation stress. In the plants growing under phosphate starvation for 21 days, the expression was even higher. This could be because of the effect of senescence, as well. At last, the amplified fragment was cloned and designated as "psr12" partial clone.