ROLE OF GENETIC FACTORS IN REGULATING CADMIUM UPTAKE, TRANSPORT AND ACCUMULATION MECHANISMS AND QUANTITATIVE TRAIT LOCI MAPPING IN RICE. A REVIEW
Adnan Rasheed, Shah Fahad, M. Aamer, Murtaza Hassan, Mohd Tahir, Zheyang Wu
Abstract
Rice is an imperative staple food globally; however, it is a major source of cadmium (Cd) intake for humans. Cd is a heavy metal and it has no biological functions in plant and, thus it causes adverse effects in plant and humans. Thus, it is of the utmost importance to minimize the Cd content in rice to protect humans from its drastic effects. In this review, we discussed the mechanisms related to the uptake and translocation of Cd in rice. OsNramp5, OsHMA3 OsHMA2 are the genes responsible for Cd uptake, translocation, and sequestration in the vacuole, so modification of these genes function result in no uptake of Cd, and leading to reduction in risk of Cd toxicity in rice. The different genetic factors involved in Cd stress and accumulation are shown here and put into several categories according to their function. The identification of novel QTLs (qSH6, qSH7 and qLR3) detected for morphological traits could be cloned and transferred to develop Cd resistant rice lines. Use of mapping population and some putative quantitative traits loci related to uptake and transport could provide strong base to develop the Cd tolerant genotypes. In addition, use of different agronomic practices may be more fruitful to minimize Cd in rice.