Starch accounts for up to 90% of the dry weight of rice endosperm and is a key determinant of grain quality. Although starch biosynthesis enzymes have been comprehensively studied, transcriptional regulation of starch-synthesis enzyme-coding genes (SECGs) is largely unknown. In this study, we explored the role of a NAC transcription factor, OsNAC24, in regulating starch biosynthesis in rice.
View Article and Find Full Text PDFMapping of QTLs for dorsal aleurone thickness (DAT) was performed using chromosome segment substitution lines in rice. Three QTLs, qDAT3.1, qDAT3.
View Article and Find Full Text PDFRice is a major food crop that sustains approximately half of the world population. Recent worldwide improvements in the standard of living have increased the demand for high-quality rice. Accurate identification of quantitative trait loci (QTLs) for rice grain quality traits will facilitate rice quality breeding and improvement.
View Article and Find Full Text PDFGrain size and the endosperm starch content determine grain yield and quality in rice. Although these yield components have been intensively studied, their regulatory mechanisms are still largely unknown. In this study, we show that loss-of-function of , a member of the NAC transcription factor gene family that has its highest expression in the immature seed, greatly increased grain length, grain weight, apparent amylose content (AAC), and plant height.
View Article and Find Full Text PDFAs sessile organisms, plants have evolved numerous strategies to acclimate to changes in environmental temperature. However, the molecular basis of this acclimation remains largely unclear. In this study we identified a tRNA guanylyltransferase, AET1, which contributes to the modification of pre-tRNA and is required for normal growth under high-temperature conditions in rice.
View Article and Find Full Text PDFGrain number and size are interactive agronomic traits that determine grain yield. However, the molecular mechanisms responsible for coordinating the trade-off between these traits remain elusive. Here, we characterized the rice () () mutant, which has larger grains but sparser panicles than the wild type due to disordered localized cell differentiation and proliferation.
View Article and Find Full Text PDFIn flowering plants, photoperiodic flowering is controlled by a complicated network. Light is one of the most important environmental stimuli that control the timing of the transition from vegetative growth to reproductive development. Several photoreceptors, including PHYA, PHYB, CRY2, and FKF1 in Arabidopsis and their homologs (OsPHYA, OsPHYB, OsPHYC, and OsCRY2) in rice, have been identified to be related to flowering.
View Article and Find Full Text PDFNatural disasters, including drought and salt stress, seriously threaten food security. In previous work we cloned a key zinc finger transcription factor gene, Drought and Salt Tolerance (DST), a negative regulator of drought and salt tolerance that controls stomatal aperture in rice. However, the exact mechanism by which DST regulates the expression of target genes remains unknown.
View Article and Find Full Text PDFFluoride compounds are abundant and widely distributed in the environment at a variety of concentrations. Further, fluoride induces toxic effects in target organs such as the liver. In this study, we investigated liver histopathology, DNA damage, apoptosis, and the mRNA and protein expressions of caspase-3 and -9 in the rat livers by administering varying concentrations of fluoride (0, 50, 100, 200 mg/L ) for 120 days.
View Article and Find Full Text PDFYoung organisms have relatively strong resistance to diseases and adverse conditions. When confronted with adversity, the process of development is delayed in plants. This phenomenon is thought to result from the rebalancing of energy, which helps plants to coordinate the relationship between development and stress tolerance; however, the molecular mechanism underlying this phenomenon remains mysterious.
View Article and Find Full Text PDFLong-term excessive sodium fluoride (NaF) intake can cause many bone diseases and nonskeletal fluorosis. The kidneys are the primary organs involved in the excretion and retention of NaF. The objective of the present study was to determine the effects of NaF treatment on renal cell apoptosis, DNA damage, and the protein expression levels of cytosolic cytochrome C (Cyt C) and cleaved caspases 9, 8, and 3 in vivo.
View Article and Find Full Text PDFThe biological effects of fluoride on human health are often extensive, either beneficial or detrimental. Among the various effects of fluoride exposure in different organs, the reproductive tract is particularly susceptible to disruption by fluoride at a sufficient concentration. It has attracted much attention to the effect of sodium fluoride on male fertility, gestational female, and offspring.
View Article and Find Full Text PDFReproductive barriers perform a vital role during speciation. Hybrid weakness, the poorer development of hybrids compared with their parents, hinders gene exchange between different species at the postzygotic stage. Here we show that two incompatible dominant loci (Hwi1 and Hwi2) involving three genes are likely to determine the high temperature-dependent expression of hybrid weakness in interspecific hybrids of rice.
View Article and Find Full Text PDFHybrid weakness is an important reproductive barrier that hinders genetic exchange between different species at the post-zygotic stage. However, our understanding of the molecular mechanisms underlying hybrid weakness is limited. In this study, we report discovery of a novel interspecific hybrid weakness in a rice chromosome segment substitution line (CSSL) library derived from a cross between the indica variety Teqing (Oryza sativa) and common wild rice (O.
View Article and Find Full Text PDFIncreased crop yields are required to support rapid population growth worldwide. Grain weight is a key component of rice yield, but the underlying molecular mechanisms that control it remain elusive. Here, we report the cloning and characterization of a new quantitative trait locus (QTL) for the control of rice grain length, weight and yield.
View Article and Find Full Text PDFMost agronomic traits are governed by quantitative trait loci (QTLs) and exhibit continuous distribution in a segregating population. The hereditary characteristics of these traits are more complicated than those of monogenic traits. Detection and isolation of these QTLs can greatly improve crop production throughout the world.
View Article and Find Full Text PDFRice grain shape, grain length (GL), width (GW), thickness (GT) and length-to-width ratio (LWR), are usually controlled by multiple quantitative trait locus (QTL). To elucidate the genetic basis of extremely large grain shape, QTL analysis was performed using an F(2) population derived from a cross between a japonica cultivar 'JZ1560' (extremely large grain) and a contrasting indica cultivar 'FAZ1' (small grain). A total number of 24 QTLs were detected on seven different chromosomes.
View Article and Find Full Text PDFLutein is the most abundant plant carotenoid and plays essential roles in photosystem assembly and stabilization, as well as protection against photostress. To date, only a few lutein biosynthesis genes have been identified in crop plants. In this study, the rice Cyt P450 gene CYP97A4 encoding a carotenoid β-ring hydroxylase was shown to be involved in lutein biosynthesis.
View Article and Find Full Text PDFPlant seed oil is important for human dietary consumption and industrial application. The oil trait is controlled by quantitative trait loci (QTLs), but no QTLs for fatty acid composition are known in rice, the monocot model plant. QTL analysis was performed using F(2) and F(2:3) progeny from a cross of an indica variety and a japonica variety.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
April 2010
Plant high-affinity K(+) transport (HKT) proteins are so named because of their relation to bacterial and fungal transporters that mediate high-affinity K(+) uptake. The view that HKT family members are sodium-selective uniporters or sodium-potassium symporters is widely held. We have found that one of the rice HKT proteins also functions as a Ca(2+)-permeable cation channel that conducts current carried by a wide range of monovalent and divalent cations.
View Article and Find Full Text PDFA CSSL (chromosome segment substitution line), SG-64, carrying a segment of chromosome 4 from African cultivated rice (CG-14) in the genetic background of var. Wuyujing-7 (japonica), showed a spreading panicle, which was different significantly from that of Wuyujing-7 with an erect compact panicle. The gene controlling a spreading panicle is referred to as Spr3, and is mapped on chromosome 4.
View Article and Find Full Text PDFAbiotic stresses, such as drought and salinity, lead to crop growth damage and a decrease in crop yields. Stomata control CO(2) uptake and optimize water use efficiency, thereby playing crucial roles in abiotic stress tolerance. Hydrogen peroxide (H(2)O(2)) is an important signal molecule that induces stomatal closure.
View Article and Find Full Text PDFIdentification of genes in rice that affect production and quality is necessary for improving the critical global food source. CSSL58, a chromosome segment substitution line (CSSL) containing a chromosome segment of Oryza rufipogon in the genetic background of the indica cultivar Teqing showed significantly smaller panicles, fewer grains per panicle, smaller grains and dwarfness compared with the recurrent parent Teqing. Genetic analysis of the BC(4)F(1) and BC(4)F(2) generations, derived from a cross between CSSL58 and Teqing, showed that these traits are controlled by the recessive gene spd6, which mapped to the short arm of chromosome 6.
View Article and Find Full Text PDF