Arsenate Phytoremediation-linked Genes in Egyptian 2 Rice Cultivars as Soil Pollution DNA Geno-Sensor 3 4

Rice (Oryza sativa L.) is the most important crop all over the world. It is considered the main 19 food of 50% of the world population especially in Egypt. However, rice not only accumulates some of 20 heavy metals such as cadmium but also accumulate arsenate (As). Arsenic contamination in water and 21 food resulted in many implications for millions of people leading cancer. For that reason, three local rice 22 cultivars; Sakha 102, 103 and 104 were propagated on modified Murashige and Skoog Basal Medium 23 (MS medium) containing elevated concentrations of arsenate (0.1, 1 and 10 mg/l). The three varieties 24 showed different resistant attitudes against arsenate. Extracted messenger RNA (mRNA) from treated 25 and untreated Sakha 104 plantlets was scanned using differential display to demonstrate the 26 differentially expressed genes in response to arsenate contamination. About 100 different RNAs with 27 molecular sizes ranged between 1500 bp 50 bp were obtained. Seven up-regulated and several down 28 regulated genes were observed. The seven up regulated genes were sequenced and the sequence 29 analysis described four genes are; disease resistance protein RPM1, Epstein-Barr virus EBNA-1-like, 30 CwfJ family protein and outer membrane lipoprotein OmlA while the other three genes were 31 hypothetical proteins. The four up regulated genes showed different percentage of similarity with other 32 well identified genes that play role in arsenate phytoremediation such as; arsenate reductase, oxidase 33 and aminoacylase 1. These genes were specifically induced in respond to the presense of arsnate in rice 34 soil and they share in pathway to phytoremidate arsenate by the rice. In future work these genes can be 35 used as geno-sensors for rice grains and soil contamination with As (V). 36