Generation and characterization of low phytic acid germplasm in rice (Oryza sativa L.)

Abstract

Phytic acid (PA, myo-inositol 1,2,3,4,5,6-hexakisphosphate), or its salt form, phytate, is commonly regarded as the major anti-nutritional component in cereal and legume grains. Breeding of low phytic acid (lpa) crops has recently been considered as a potential way to increase nutritional quality of crop products. In this study, eight independent lpa rice mutant lines from both indica and japonica subspecies were developed through physical and chemical mutagenesis. Among them, five are non-lethal while the other three are homozygous lethal. None of the lethal lines could produce homozygous lpa plants through seed germination and growth under field conditions, but two of them could be rescued through in vitro culture of mature embryos. The non-lethal lpa mutants had lower PA content ranging from 34 to 64% that of their corresponding parent and four of them had an unchanged total P level. All the lpa mutations were inherited in a single recessive gene model and at least four lpa mutations were identified mutually non-allelic, while the other two remain to be verified. One mutation was mapped on chromosome 2 between microsatellite locus RM3542 and RM482, falling in the same region as the previously mapped lpa1-1 locus did; another lpa mutation was mapped on chromosome 3, tightly linked to RM3199 with a genetic distance of 1.198 cM. The latter mutation was very likely to have happened to the LOC_Os03g52760, a homolog of the maize myo-inositol kinase (EC 2.7.1.64) gene. The present work greatly expands the number of loci that could influence the biosynthesis of PA in rice, making rice an excellent model system for research in this area.

TheArabidopsis thaliana Myo-Inositol 1-Phosphate Synthase1 Gene Is Required forMyo-inositol Synthesis and Suppression of Cell Death

“…2000; Dorsch et al, 2003;Liu et al, 2007;Yuan et al, 2007). Our work on the MIPS genes in the model plant Arabidopsis points to specialized roles for individual MIPS genes, with the MIPS1 gene providing the greatest impact, overall, on myo-inositol, growth, development, and physiology.…”

Biofortification of Wheat with Iron

“…In addition to that, a transporter ABC is required for transport and final step compartmentalization which can be disrupted to disturb biosynthesis pathway of phytic acid [56]. Many mutant lines have been reported in different plant species such as wheat [57], maize [58;59], rice [60,61], soybean [62,63] and Arabidopsis [64,64]. Although, conventional breeding may result in strong reduction and phytic acid and IJASR|VOL 03|ISSUE 07|2017 www.ssjournals.com the lpa mutants may also have negative effects such as reduced seedling and slow germination which effect on growth of the plants.…”

Nutritionally Enhanced Staple Food Crops

“…Studies of germplasm collections have revealed significant genetic variation for both seed phytate and/or total P in common bean, lentil, sorghum, soybean, and wheat (Lolas and Markakis 1975;Raboy et al 1991;Israel et al 2006;Kayode et al 2006;Ficco et al 2009;Thavarajah et al 2010;Akond et al 2011). Likewise, researchers have used both chemical and physical mutagens to isolate lp mutants in barley (Raboy 2000;Bowen et al 2006), common bean (Campion et al 2009), maize (Raboy 2000;Badone et al 2010), rice (Larson et al 2000;Raboy 2000;Rutger et al 2004;Liu et al 2007;Kim et al 2008), soybean (Wilcox et al 2000;Walker et al 2006), and wheat (Guttieri et al 2004). These studies reported two types of mutants, those with moderate reduction (50%-65%) or extreme reduction (95%) in phytic acid, with the latter being homozygotes and lethal.…”