Dealing with iron metabolism in rice: from breeding for stress tolerance to biofortification

Abstract

Iron is a well-known metal. Used by humankind since ancient times in many different ways, this element is present in all living organisms, where, unfortunately, it represents a two-way problem. Being an essential block in the composition of different proteins and metabolic pathways, iron is a vital component for animals and plants. That is why iron deficiency has a severe impact on the lives of different organisms, including humans, becoming a major concern, especially in developing countries where access to adequate nutrition is still difficult. On the other hand, this metal is also capable of causing damage when present in excess, becoming toxic to cells and affecting the whole organism. Because of its importance, iron absorption, transport and storage mechanisms have been extensively investigated in order to design alternatives that may solve this problem. As the understanding of the strategies that plants use to control iron homeostasis is an important step in the generation of improved plants that meet both human agricultural and nutritional needs, here we discuss some of the most important points about this topic.

Effects of Iron on the Productivity of Lowland Rice (O. sativa L.) in Segregating Populations

“…Iron is a trace element is very important for rice plants for growth and development, especially for grain yield production through efficiency of photosynthesis by maintaining high chlorophyll production. However, when in excess, it becomes a highly toxic element [5,6]. Rice yield loss due to iron toxicity ranges from 10% to 100%, depending on the severity of the toxicity and the tolerance of rice varieties.…”

Iron biofortification in rice: in search of morphological traits for indirect selection in breeding programs

“…Efforts have been carried out, for example, in the development of transgenic plants, and different genes were assayed. Even though the strategies using genetic transformation resulted in the increase of Fe content, milling is still responsible for many losses (revised by Santos et al, 2017). Thus, the conventional selection of genotypes with high Fe content followed by hybridization continue to be an interesting alternative.…”

Selection and testing of reference genes for accurate RT-qPCR in rice seedlings under iron toxicity

“…These results suggest that transcriptional stability is dependent on tissue, genotype and the experimental conditions to which it has been subjected, and that the use of multiple reference genes is recommended for better normalization. Although studies of gene expression through RT-qPCR have been made with rice under stress by iron [ 13 ], this represents the first effort to investigate the transcriptional behavior of reference genes in rice under iron excess, an important condition of abiotic stress that is still neglected by studies in the field of molecular biology.…”

“…Among the most important abiotic stresses in rice is iron toxicity, a root related stress, that is usually associated with flooded soils and consequently with lowland production systems. In the absence of oxygen high concentrations of reduced iron (Fe 2+ ) become available in soil solution and the excessive uptake of this element can damage rice plants in several ways [ 13 ].…”