Genetically engineered rice with appA gene enhanced phosphorus and minerals

Abstract

Phytic acid is the major source of phosphorus and other mineral bound compounds in many plant tissues especially seeds and bran of cereals. During germination, phytase enzyme degrades phytic acid and bound phosphate and minerals are released. The monogastric animal cannot digest phytate due to lack of the phytase enzyme. Considering that, we have generated low phytate rice by over expressing appA gene cloned from E. coli under the aleurone-specific promoter of maize zein gene. Molecular analysis confirmed the stable integration of transgene and plants were grown up to T3 generation. The T3 seeds showed around 45% decrease in seed phytate content with a fourfold increase of inorganic phosphorus (Pi) level. The enhanced iron and zinc was twofold and threefold respectively in polished seeds of transgenic plants. There was no change in germination behaviour and other morphological traits in transgenic seeds. Thus, this result provides evidence that tissue-specific expression of bacterial phytase can lead to the reduction of phytic acid in rice seeds without hampering its other physiological processes and phenotypic cost.