Rice Genotypes with SUB1 QTL Differ in Submergence Tolerance, Elongation Ability during Submergence and Re-generation Growth at Re-emergence
Ontology highlight
ABSTRACT:
SUBMITTER: Sarkar R
PROVIDER: S-EPMC5520825 | biostudies-literature | 2011 Nov
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Background and aimsSubmergence tolerance in rice is primarily attributed to the action of the SUB1 gene, but other associated traits such as leaf gas film (LGF) thickness, leaf hydrophobicity, porosity and leaf density have been known to aid submergence tolerance in rice. However, association of these traits with SUB1 quantitative trait locus (QTL) has not been demonstrated. In this study, we aim to investigate (1) whether the presence of the SUB1 QTL in the genetic background has any influence on the thickness of the LGF and (ii) whether its removal has any impact on stress perception and submergence tolerance in Sub1 and non-Sub1 rice.MethodsWe examined 12 genotypes (including both Sub1 and non-Sub1 types) for different leaf traits such as initial LGF thickness, leaf hydrophobicity, tissue porosity and leaf density in order to work out the relatioship of these traits to the SUB1 QTL in rice. Furthermore, we investigated the changes in the gene expression profile and different metabolic processes in selected genotypes in the presence and absence of their LGF to study its impact on stress perception and adaptation.Key resultsThe initial thickness of the LGF and hydrophobicity seemed to have a highly positive correlation with the presence of the SUB1 QTL in the genetic background of rice; however, other leaf traits such as porosity and density seemed to be independent of it. Artificial removal of the LGF resulted in partial loss of tolerance, showing increased ethylene production and early induction of anoxia-related genes (SUB1A-1, ACS5, Ramy3D and ADH1) which manifested symptoms such as increased stem elongation, faster chlorophyll and starch breakdown, and partial loss of quiescence in SUB1-containing rice genotypes. Stripping of the LGF resulted in early and enhanced induction of SUB1A-1, indicating a quicker perception of stress.ConclusionsThe presence of SUB1 in the genetic background positively influences surface hydrophobicity and the concomitant LGF thickness of rice. Furthermore, LGF helps in terms of providing better ethylene dissipation and reduced in planta accumulation, owing to the slowing down of ethylene-induced leaf senescence under submergence stress.
| S-EPMC7789114 | biostudies-literature
Project description:Background and aimsTolerance of complete submergence is recognized in a small number of accessions of domesticated Asian rice (Oryza sativa) and can be conferred by the Sub1A-1 gene of the polygenic Submergence-1 (Sub1) locus. In all O. sativa varieties, the Sub1 locus encodes the ethylene-responsive factor (ERF) genes Sub1B and Sub1C. A third paralogous ERF gene, Sub1A, is limited to a subset of indica accessions. It is thought that O. sativa was domesticated from the gene pools of the wild perennial species O. rufipogon Griff. and/or the annual species O. nivara Sharma et Shastry. The aim of this study was to evaluate the orthologues of the Sub1 locus in the closest relatives of O. sativa to provide insight into the origin of the gene and allelic variation of the Sub1 locus.MethodsOrthologues of the Sub1 genes were isolated from O. rufipogon and O. nivara by use of oligonucleotide primers corresponding to the most highly conserved regions of the Sub1 genes of domesticated rice. The phylogenetic relatedness of Sub1 genes of O. sativa and its wild relatives was evaluated.Key results and conclusionsBoth O. rufipogon and O. nivara possess two Sub1 gene orthologues with strong sequence identity to the Sub1B and Sub1C alleles of cultivated rice. The phylogeny of the Sub1 genes of the domesticated and wild rice suggests that Sub1A arose from duplication of Sub1B. Variation in Sub1B alleles is correlated with the absence or presence of Sub1A. Together, the results indicate that genetic variation at the Sub1 locus is due to gene duplication and divergence that have occurred both prior to and after rice domestication.
| S-EPMC2707309 | biostudies-literature
Project description:Global climate change has increased the number of severe flooding events that affect agriculture, including rice production in the U.S. and internationally. Heavy rainfall can cause rice plants to be completely submerged, which can significantly affect grain yield or completely destroy the plants. Recently, a major effect submergence tolerance QTL during the vegetative stage, qSub8.1, which originated from Ciherang-Sub1, was identified in a mapping population derived from a cross between Ciherang-Sub1 and IR10F365. Ciherang-Sub1 was, in turn, derived from a cross between Ciherang and IR64-Sub1. Here, we characterize the qSub8.1 region by analyzing the sequence information of Ciherang-Sub1 and its two parents (Ciherang and IR64-Sub1) and compare the whole genome profile of these varieties with the Nipponbare and Minghui 63 (MH63) reference genomes. The three rice varieties were sequenced with 150 bp pair-end whole-genome shotgun sequencing (Illumina HiSeq4000), followed by performing the Trimmomatic-SOAPdenovo2-MUMmer3 pipeline for genome assembly, resulting in approximate genome sizes of 354.4, 343.7, and 344.7 Mb, with N50 values of 25.1, 25.4, and 26.1 kb, respectively. The results showed that the Ciherang-Sub1 genome is composed of 59-63% Ciherang, 22-24% of IR64-Sub1, and 15-17% of unknown sources. The genome profile revealed a more detailed genomic composition than previous marker-assisted breeding and showed that the qSub8.1 region is mostly from Ciherang, with some introgressed segments from IR64-Sub1 and currently unknown source(s).
| S-EPMC8703405 | biostudies-literature
Project description:Rice has the natural morphological adaptation to germinate and elongate its coleoptile under submerged flooding conditions. The phenotypic deviation associated with the tolerance to submergence at the germination stage could be due to natural variation. However, the molecular basis of this variation is still largely unknown. A comprehensive understanding of gene regulation of different genotypes that have diverse rates of coleoptile elongation can provide significant insights into improved rice varieties. To do so, publicly available transcriptome data of five rice genotypes, which have different lengths of coleoptile elongation under submergence tolerance, were analyzed. The aim was to identify the correlation between promoter architecture, associated with transcriptional and hormonal regulation, in diverse genotype groups of rice that have different rates of coleoptile elongation. This was achieved by identifying the putative cis-elements present in the promoter sequences of genes upregulated in each group of genotypes (tolerant, highly tolerant, and extremely tolerant genotypes). Promoter analysis identified transcription factors (TFs) that are common and unique to each group of genotypes. The candidate TFs that are common in all genotypes are MYB, bZIP, AP2/ERF, ARF, WRKY, ZnF, MADS-box, NAC, AS2, DOF, E2F, ARR-B, and HSF. However, the highly tolerant genotypes interestingly possess binding sites associated with HY5 (bZIP), GBF3, GBF4 and GBF5 (bZIP), DPBF-3 (bZIP), ABF2, ABI5, bHLH, and BES/BZR, in addition to the common TFs. Besides, the extremely tolerant genotypes possess binding sites associated with bHLH TFs such as BEE2, BIM1, BIM3, BM8 and BAM8, and ABF1, in addition to the TFs identified in the tolerant and highly tolerant genotypes. The transcriptional regulation of these TFs could be linked to phenotypic variation in coleoptile elongation in response to submergence tolerance. Moreover, the results indicate a cross-talk between the key TFs and phytohormones such as gibberellic acid, abscisic acid, ethylene, auxin, jasmonic acid, and brassinosteroids, for an altered transcriptional regulation leading to differences in germination and coleoptile elongation under submergence. The information derived from the current in silico analysis can potentially assist in developing new rice breeding targets for direct seeding.
| S-EPMC8008075 | biostudies-literature
Project description: Not available
| S-EPMC11678009 | biostudies-literature
Project description:Flash flooding of young rice plants is a common problem for rice farmers in south and south-east Asia. It severely reduces grain yield and increases the unpredictability of cropping. The inheritance and expression of traits associated with submergence stress tolerance at the seedling stage are physiologically and genetically complex. We exploited naturally occurring differences between certain rice lines in their tolerance to submergence and used quantitative trait loci (QTL) mapping to improve understanding of the genetic and physiological basis of submergence tolerance. Three rice populations, each derived from a single cross between two cultivars differing in their response to submergence, were used to identify QTL associated with plant survival and various linked traits. These included total shoot elongation under water, the extent of stimulation of shoot elongation caused by submergence, a visual submergence tolerance score, and leaf senescence under different field conditions, locations and years. Several major QTL determining plant survival, plant height, stimulation of shoot elongation, visual tolerance score and leaf senescence each mapped to the same locus on chromosome 9. These QTL were detected consistently in experiments across all years and in the genetic backgrounds of all three mapping populations. Secondary QTL influencing tolerance were also identified and located on chromosomes 1, 2, 5, 7, 10 and 11. These QTL were specific to particular traits, environments, or genetic backgrounds. All identified QTL contributed to increased submergence tolerance through their effects on decreased underwater shoot elongation or increased maintenance of chlorophyll levels, or on both. These findings establish the foundations of a marker-assisted scheme for introducing submergence tolerance into agriculturally desirable cultivars of rice.
| S-EPMC4244984 | biostudies-literature
Project description:In the recent time, Submergence1 (Sub1)QTL, responsible for imparting tolerance to flash flooding, has been introduced in many rice cultivars, but resilience of the QTL to stagnant flooding (SF) is not known. The response of Sub1-introgression has been tested on physiology, molecular biology and yield of two popular rice cultivars (Swarna and Savitri) by comparison of the parental and Sub1-introgression lines (SwarnaSub1 and SavitriSub1) under SF. Compared to control condition SF reduced grain yield and tiller number and increased plant height and Sub1- introgression mostly matched these effects. SF increased ethylene production by over-expression of ACC-synthase and ACC-oxidase enzyme genes of panicle before anthesis in the parental lines. Expression of the genes changed with Sub1-introgression, where some enzyme isoform genes over-expressed after anthesis under SF. Activities of endosperm starch synthesizing enzymes SUS and AGPase declined concomitantly with rise ethylene production in the Sub1-introgressed lines resulting in low starch synthesis and accumulation of soluble carbohydrates in the developing spikelets. In conclusion, Sub1-introgression into the cultivars increased susceptibility to SF. Subjected to SF, the QTL promoted genesis of ethylene in the panicle at anthesis to the detriment of grain yield, while compromising with morphological features like tiller production and stem elongation.
| S-EPMC6898156 | biostudies-literature
Project description:TDK1 is a popular rice variety from the Lao PDR. Originally developed for irrigated conditions, this variety suffers a high decline in yield under drought conditions. Studies have identified three quantitative trait loci (QTLs) for grain yield under drought conditions, qDTY3.1 , qDTY6.1 , and qDTY6.2 , that show a high effect in the background of this variety. We report here the pyramiding of these three QTLs with SUB1 that provides 2-3 weeks of tolerance to complete submergence, with the aim to develop drought- and submergence-tolerant near-isogenic lines (NILs) of TDK1. We used a tandem approach that combined marker-assisted backcross breeding with phenotypic selection to develop NILs with high yield under drought stress and non-stress conditions and preferred grain quality. The effect of different QTL combinations on yield and yield-related traits under drought stress and non-stress conditions is also reported. Our results show qDTY3.1 to be the largest and most consistent QTL affecting yield under drought conditions, followed by qDTY6.1 and qDTY6.2 , respectively. QTL class analysis also showed that lines with a combination of qDTY3.1 and qDTY6.1 consistently showed a higher tolerance to drought than those in which one of these QTLs was missing. In countries such as Lao PDR, where large areas under rice cultivation suffer vegetative-stage submergence and reproductive-stage drought, these lines could ensure yield stability. These lines can also serve as valuable genetic material to be used for further breeding of high-yielding, drought- and submergence-tolerant varieties in local breeding programs.
| S-EPMC5670188 | biostudies-literature
Project description:Drought and submergence have been the major constraint in rice production. The present study was conducted to develop high-yielding rice lines with tolerance to drought and submergence by introgressing Sub1 into a rice line with drought yield QTL (qDTY; QTL = quantitative trait loci) viz. qDTY3.1 and qDTY12.1 using marker-assisted breeding. We report here the effect of different combinations of Sub1 and qDTY on morpho-physiological, agronomical traits and yield under reproductive stage drought stress (RS) and non-stress (NS) conditions. Lines with outstanding performance in RS and NS trials were also evaluated in vegetative stage submergence stress (VS) trial to assess the tolerance level. The QTL class analysis revealed Sub1 + qDTY3.1 as the best QTL combination affecting the measured traits in RS trial followed by Sub1 + qDTY12.1. The effects of single Sub1, qDTY3.1 and qDTY12.1 were not as superior as when the QTLs are combined, suggesting the positive interaction of Sub1 and qDTY. Best performing lines selected from the RS and NS trials recorded yield advantage up to 4453.69 kg ha-1 and 6954 kg ha-1 over the parents, respectively. The lines were also found having great tolerance to submergence ranging from 80% to 100%, contributed by a lower percentage of shoot elongation and reduction of chlorophyll content after 14 days of VS. These lines could provide yield sustainability to farmers in regions impacted with drought and submergence while serving as important genetic materials for future breeding programs.
| S-EPMC7912027 | biostudies-literature
Project description:By the year 2100, the number of people on Earth is expected to increase by ∼50%, placing increasing demands on food production in a time when a changing climate is predicted to compromise crop yields. Feeding this future world requires scientifically informed innovations in agriculture. Here, we describe how a rice gene conferring tolerance to prolonged submergence has helped farmers in South and Southeast Asia mitigate rice crop failure during floods. We discuss how planting of this new variety benefited socially disadvantaged groups. This example indicates that investment in agricultural improvement can protect farmers from risks associated with a changing climate.
| S-EPMC6886445 | biostudies-literature