Genetic determinants controlling maize rubisco activase gene expression and a comparison with rice counterparts.

BACKGROUND: Rubisco activase (RCA) regulates the activity of Rubisco and is a key enzyme of photosynthesis. RCA expression was widely reported to affect plant photosynthesis and crop yield, but the molecular basis of natural variation in RCA expression in a wide range of maize materials has not been fully elucidated. RESULTS: In this study, correlation analysis in approximately 200 maize inbred lines revealed a significantly positive correlation between the expression of maize RCA gene ZmRCAß and grain yield. A genome-wide association study revealed both cis-expression quantitative trait loci (cis-eQTLs) and trans-eQTLs underlying the expression of ZmRCAß, with the latter playing a more important role. Further allele mining and genetic transformation analysis showed that a 2-bp insertion and a 14-bp insertion in the promoter of ZmRCAß conferred increased gene expression. Because rice is reported to have higher RCA gene expression than does maize, we subsequently compared the genetic factors underlying RCA gene expression between maize and rice. The promoter activity of the rice RCA gene was shown to be stronger than that of the maize RCA gene, suggesting that replacing the maize RCA gene promoter with that of the rice RCA gene would improve the expression of RCA in maize. CONCLUSION: Our results revealed two DNA polymorphisms regulating maize RCA gene ZmRCAß expression, and the RCA gene promoter activity of rice was stronger than that of maize. This work increased understanding of the genetic mechanism that underlies RCA gene expression and identify new targets for both genetic engineering and selection for maize yield improvement.

Multifaceted plant G protein: interaction network, agronomic potential, and beyond.

MAIN CONCLUSION: Heterotrimeric G protein and interacting effectors are relevant for agronomic significance. We can manipulate G protein and effectors, individually or in combination, to develop plant ideotypes by intelligent design breeding. Heterotrimeric guanine nucleotide-binding protein (G protein) is involved in a wide range of biological events, many of which with agronomic significance. In this review, we summarize recent advances of plant G protein research. We first retrieve maize G protein core subunits Gα, Gß, and Gγ based on information of Arabidopsis and rice G proteins using integrated BLAST and domain confirmation. Then, we briefly introduce the distribution and function of G protein. We also describe the interaction between G protein and CLAVATA receptor, brassinosteroid signaling kinase complex, and MADS-domain transcription factor. Finally, we discuss the application of G protein knowledge in intelligent plant breeding with focus on the improvement of agronomically important traits.

Maize transcriptomic repertoires respond to gibberellin stimulation.

Phytohormone gibberellin (GA) serves as hub modulator of diverse biological events. Understanding the transcriptomic features of GA-mediated processes has scientific significance. The transcriptomic landscapes of cereal crops upon GA stimulation remains largely unknown. Herein, to reveal the transcriptomic changes in cereal crop maize under GA treatment, we first selected normal height and GA-sensitive maize dwarf plants from advanced backcross population for GA treatment. RNA-seq analysis discovered multiple protein-coding transcripts that were differentially expressed in GA-treated samples compared to distilled water-treated ones. Some differentially expressed transcripts, namely GA-responsive transcripts in this study, encoded the components of GA pathway, including CPS, KS, and KO enzymes for GA biosynthesis, GA2ox enzymes for GA degradation, DELLA repressors and GID1 receptor for GA signaling. A total of 214 shared GA-responsive transcripts were identified both in GA3-treated normal height and GA-sensitive dwarf samples. Shared GA-responsive transcripts were involved in GA signaling, auxin biosynthesis, ethylene response, the composition and structure of cell wall, chlorophyll biogenesis, and sugar homeostasis. In addition, the convergence and divergence in expression of shared GA-responsive transcripts were observed in GA3-treated normal height and GA-sensitive dwarf plants. Interaction network modeling indicated that some shared GA-responsive transcripts tended to be co-regulated, which increases the complexity of GA-triggered regulation at transcriptomic layer. Results presented here will extend our knowledge of GA-mediated regulatory cascade, and enhance our ability to apply hormone GA knowledge in agricultural practice.

On Connectivity and Energy Efficiency for Sleeping-Schedule-Based Wireless Sensor Networks.

Based on the connectivity and energy consumption problems in wireless sensor networks, this paper proposes a kind of new network algorithm called the connectivity and energy efficiency (CEE) algorithm to guarantee the connectivity and connectivity probability, and also to reduce the network energy consumption as much as possible. Under the premise that all sensors can communicate with each other in a specific communication radius, we obtained the relationship among the connectivity, the number of sensor nodes, and the communication radius because of the theory of probability and statistics. The innovation of the paper is to maximize the network connectivity and connectivity probability, by choosing which types of sleeping nodes to wake up. According to the node's residual energy and the relative value of distance, the algorithm reduces the energy consumption of the whole network as much as possible, and wakes up the number of neighbor nodes as little as possible, to improve the service life of the whole network. Simulation results show that this algorithm combines the connectivity and the energy efficiency, provides a useful reference value for the normal operation of the sensors networks.

Unveiling gibberellin-responsive coding and long noncoding RNAs in maize.

KEY MESSAGE: We report coding and long noncoding RNAs in maize upon phytohormone gibberellin stimulation. Plant hormone gibberellin (GA) orchestrates various facets of biological processes. Dissection the transcriptomic dynamics upon GA stimulation has biological significance. Feature of maize transcriptome in response to GA application remains largely elusive. Herein, two types of plants, one was with normal height, the other was GA-sensitive dwarfism, were selected from advanced backcross population for GA3 treatment with different concentrations. In control and GA3-treated plants, we identified a large number of coding and long noncoding RNAs (lncRNAs) through sequencing eight ribosomal-depleted RNA libraries. Transcripts encoding GA biosynthetic and metabolic enzymes KS, GA20ox, GA3ox, and GA2ox were significantly differentially expressed in GA3-treated samples. A total of 78 protein-coding transcripts were shared between GA3-treated normal height and dwarf plants. Shared transcripts encoding terpene synthase, MYB transcription factor, and receptor-like protein kinase were co-regulated with their corresponding partners. Out of identified lncRNAs, 22 and 34 significantly differentially expressed lncRNAs were responsive to GA application in normal height and dwarf plants, respectively. Shared GA-responsive lncRNAs were found in GA3-treated normal height and dwarf plants. Some lncRNAs corresponded to precursors of known miRNA, such as zma-miR528a and zma-miR528b. Multiple promising targets of significantly differentially expressed lncRNAs were discovered, including Lazy plant1 for auxin- and GA-mediated shoot gravitropism, bZIP transcription factor member for GA-controlled cell elongation. This study will improve our knowledge of GA-triggered transcriptome change and facilitate a comprehensive understanding of regulatory cascade centering on GA.

Gibberellin in plant height control: old player, new story.

Height relates to plant architecture, lodging resistance, and yield performance. Growth-promoting phytohormones gibberellins (GAs) play a pivotal role in plant height control. Mutations in GA biosynthesis, metabolism, and signaling cascades influence plant height. Moreover, GA interacts with other phytohormones in the modulation of plant height. Here, we first briefly describe the regulation of plant height by altered GA pathway. Then, we depict effects of the crosstalk between GA and other phytohormones on plant height. We also dissect the co-localization of GA pathway genes and established quantitative genetic loci for plant height. Finally, we suggest ways forward for the application of hormone GA knowledge in breeding of crops with plant height ideotypes.

Bioinformatic landscapes for plant transcription factor system research.

MAIN CONCLUSION: Diverse bioinformatic resources have been developed for plant transcription factor (TF) research. This review presents the bioinformatic resources and methodologies for the elucidation of plant TF-mediated biological events. Such information is helpful to dissect the transcriptional regulatory systems in the three reference plants Arabidopsis , rice, and maize and translation to other plants. Transcription factors (TFs) orchestrate diverse biological programs by the modulation of spatiotemporal patterns of gene expression via binding cis-regulatory elements. Advanced sequencing platforms accompanied by emerging bioinformatic tools revolutionize the scope and extent of TF research. The system-level integration of bioinformatic resources is beneficial to the decoding of TF-involved networks. Herein, we first briefly introduce general and specialized databases for TF research in three reference plants Arabidopsis, rice, and maize. Then, as proof of concept, we identified and characterized heat shock transcription factor (HSF) members through the TF databases. Finally, we present how the integration of bioinformatic resources at -omics layers can aid the dissection of TF-mediated pathways. We also suggest ways forward to improve the bioinformatic resources of plant TFs. Leveraging these bioinformatic resources and methodologies opens new avenues for the elucidation of transcriptional regulatory systems in the three model systems and translation to other plants.

A comprehensive meta-analysis of plant morphology, yield, stay-green, and virus disease resistance QTL in maize (Zea mays L.).

MAIN CONCLUSION: The meta-QTL and candidate genes will facilitate the elucidation of molecular bases underlying agriculturally important traits and open new avenues for functional markers development and elite alleles introgression in maize breeding program. A large number of QTLs attributed to grain productivity and other agriculturally important traits have been identified and deposited in public repositories. The integration of fruitful QTL becomes a major issue in current plant genomics. To this end, we first collected QTL for six agriculturally important traits in maize, including yield, plant height, ear height, leaf angle, stay-green, and maize rough dwarf disease resistance. The meta-analysis method was then employed to retrieve 113 meta-QTL. Additionally, we also isolated candidate genes for target traits by the bioinformatic technique. Several candidates, including some well-characterized genes, GA3ox2 for plant height, lg1 and lg4 for leaf angle, zfl1 and zfl2 for flowering time, were co-localized with established meta-QTL intervals. Intriguingly, in a relatively narrow meta-QTL region, the maize ortholog of rice yield-related gene GW8/OsSPL16 was believed to be a candidate for yield. Leveraging results presented in this study will provide further insights into the genetic architecture of maize agronomic traits. Moreover, the meta-QTL and candidate genes reported here could be harnessed for the enhancement of stress tolerance and yield performance in maize and translation to other crops.

A maize phytochrome-interacting factor 3 improves drought and salt stress tolerance in rice.

Phytochrome-interacting factor 3 (PIF3) activates light-responsive transcriptional network genes in coordination with the circadian clock and plant hormones to modulate plant growth and development. However, little is known of the roles PIF3 plays in the responses to abiotic stresses. In this study, the cloning and functional characterization of the ZmPIF3 gene encoding a maize PIF3 protein is reported. Subcellular localization revealed the presence of ZmPIF3 in the cell nucleus. Expression patterns revealed that ZmPIF3 is expressed strongly in leaves. This expression responds to polyethylene glycol, NaCl stress, and abscisic acid application, but not to cold stress. ZmPIF3 under the control of the ubiquitin promoter was introduced into rice. No difference in growth and development between ZmPIF3 transgenic and wild-type plants was observed under normal growth conditions. However, ZmPIF3 transgenic plants were more tolerant to dehydration and salt stresses. ZmPIF3 transgenic plants had increased relative water content, chlorophyll content, and chlorophyll fluorescence, as well as significantly enhanced cell membrane stability under stress conditions. The over-expression of ZmPIF3 increased the expression of stress-responsive genes, such as Rab16D, DREB2A, OSE2, PP2C, Rab21, BZ8 and P5CS, as detected by real-time PCR analysis. Taken together, these results improve our understanding of the role ZmPIF3 plays in abiotic stresses signaling pathways; our findings also indicate that ZmPIF3 regulates the plant response to drought and salt stresses.

Characterization of Rubisco activase genes in maize: an α-isoform gene functions alongside a ß-isoform gene.

Rubisco activase (RCA) catalyzes the activation of Rubisco in vivo and plays a crucial role in regulating plant growth. In maize (Zea mays), only ß-form RCA genes have been cloned and characterized. In this study, a genome-wide survey revealed the presence of an α-form RCA gene and a ß-form RCA gene in the maize genome, herein referred to as ZmRCAα and ZmRCAß, respectively. An analysis of genomic DNA and complementary DNA sequences suggested that alternative splicing of the ZmRCAß precursor mRNA (premRNA) at its 3' untranslated region could produce two distinctive ZmRCAß transcripts. Analyses by electrophoresis and matrix-assisted laser desorption/ionization-tandem time-of-flight mass spectrometry showed that ZmRCAα and ZmRCAß encode larger and smaller polypeptides of approximately 46 and 43 kD, respectively. Transcriptional analyses demonstrated that the expression levels of both ZmRCAα and ZmRCAß were higher in leaves and during grain filling and that expression followed a specific cyclic day/night pattern. In 123 maize inbred lines with extensive genetic diversity, the transcript abundance and protein expression levels of these two RCA genes were positively correlated with grain yield. Additionally, both genes demonstrated a similar correlation with grain yield compared with three C4 photosynthesis genes. Our data suggest that, in addition to the ß-form RCA-encoding gene, the α-form RCA-encoding gene also contributes to the synthesis of RCA in maize and support the hypothesis that RCA genes may play an important role in determining maize productivity.

Molecular basis and evolutionary pattern of GA-GID1-DELLA regulatory module.

The tetracyclic diterpenoid carboxylic acids, gibberellins (GAs), orchestrate a broad spectrum of biological programs. In nature, GAs or GA-like substance is produced in bacteria, fungi, and plants. The function of GAs in microorganisms remains largely unknown. Phytohormones GAs mediate diverse growth and developmental processes through the life cycle of plants. The GA biosynthetic and metabolic pathways in bacteria, fungi, and plants are remarkably divergent. In vascular plants, phytohormone GA, receptor GID1, and repressor DELLA shape the GA-GID1-DELLA module in GA signaling cascade. Sequence reshuffling, functional divergence, and adaptive selection are main driving forces during the evolution of GA pathway components. The GA-GID1-DELLA complex interacts with second messengers and other plant hormones to integrate environmental and endogenous cues, which is beneficial to phytohormones homeostasis and other biological events. In this review, we first briefly describe GA metabolism pathway, signaling perception, and its second messengers. Then, we examine the evolution of GA pathway genes. Finally, we focus on reviewing the crosstalk between GA-GID1-DELLA module and phytohormones. Deciphering mechanisms underlying plant hormonal interactions are not only beneficial to addressing basic biological questions, but also have practical implications for developing crops with ideotypes to meet the future demand.

Diversification, phylogeny and evolution of auxin response factor (ARF) family: insights gained from analyzing maize ARF genes.

Auxin response factors (ARFs), member of the plant-specific B3 DNA binding superfamily, target specifically to auxin response elements (AuxREs) in promoters of primary auxin-responsive genes and heterodimerize with Aux/IAA proteins in auxin signaling transduction cascade. In previous research, we have isolated and characterized maize Aux/IAA genes in whole-genome scale. Here, we report the comprehensive analysis of ARF genes in maize. A total of 36 ARF genes were identified and validated from the B73 maize genome through an iterative strategy. Thirty-six maize ARF genes are distributed in all maize chromosomes except chromosome 7. Maize ARF genes expansion is mainly due to recent segmental duplications. Maize ARF proteins share one B3 DNA binding domain which consists of seven-stranded ß sheets and two short α helixes. Twelve maize ARFs with glutamine-rich middle regions could be as activators in modulating expression of auxin-responsive genes. Eleven maize ARF proteins are lack of homo- and heterodimerization domains. Putative cis-elements involved in phytohormones and light signaling responses, biotic and abiotic stress adaption locate in promoters of maize ARF genes. Expression patterns vary greatly between clades and sister pairs of maize ARF genes. The B3 DNA binding and auxin response factor domains of maize ARF proteins are primarily subjected to negative selection during selective sweep. The mixed selective forces drive the diversification and evolution of genomic regions outside of B3 and ARF domains. Additionally, the dicot-specific proliferation of ARF genes was detected. Comparative genomics analysis indicated that maize, sorghum and rice duplicate chromosomal blocks containing ARF homologs are highly syntenic. This study provides insights into the distribution, phylogeny and evolution of ARF gene family.

Systematic analysis of plant-specific B3 domain-containing proteins based on the genome resources of 11 sequenced species.

B3 domain-containing proteins constitute a large transcription factor superfamily. The plant-specific B3 superfamily consists of four family members, i.e., LAV (LEC2 [LEAFY COTYLEDON 2]/ABI3 [ABSCISIC ACID INSENSITIVE 3] − VAL [VP1/ABI3-LIKE]), RAV (RELATED to ABI3/VP1), ARF (AUXIN RESPONSE FACTOR) and REM (REPRODUCTIVE MERISTEM) families. The B3 superfamily plays a central role in plant life, from embryogenesis to seed maturation and dormancy. In previous research, we have characterized ARF family, member of the B3 superfamily in silico (Wang et al., Mol Biol Rep, 2011, doi:10.1007/s11033-011-0991-z). In this study, we systematically analyzed the diversity, phylogeny and evolution of B3 domain-containing proteins based on genomic resources of 11 sequenced species. A total of 865 B3 domain-containing genes were identified from 11 sequenced species through an iterative strategy. The number of B3 domain-containing genes varies not only between species but between gene families. B3 domain-containing genes are unevenly distributed in chromosomes and tend to cluster in the genome. Numerous combinations of B3 domains and their partner domains contribute to the sequences and structural diversification of the B3 superfamiy. Phylogenetic results showed that moss VAL proteins are related to LEC2/ABI3 instead of VAL proteins from higher plants. Lineage-specific expansion of ARF and REM proteins was observed. The REM family is the most diversified member among the B3 superfamily and experiences a rapid divergence during selective sweep. Based on structural and phylogenetic analysis results, two possible evolutional modes of the B3 superfamily were presented. Results presented here provide a resource for further characterization of the B3 superfamily.

GmFtsH9 expression correlates with in vivo photosystem II function: chlorophyll a fluorescence transient analysis and eQTL mapping in soybean.

Filamentation temperature-sensitive H (FtsH) is an ATP-dependent zinc metalloprotease involved in diverse biological functions. There are 12 FtsH proteins in Arabidopsis, among which AtFtsH2 plays an important role in regulating the turnover of photosystem II (PSII) reaction center D1 protein and the development of the photosynthetic apparatus. Here, we have identified 11 FtsH genes in the soybean genome by a bioinformatics approach. These soybean FtsH genes corresponded to seven Arabidopsis FtsH genes, suggesting that the main characteristics of soybean FtsH genes were formed before the evolutionary split of soybean and Arabidopsis. Phylogenetic analyses allowed us to clone a soybean AtFtsH2-like gene designated as GmFtsH9. The predicted protein of GmFtsH9 consists of 690 amino acids and contains three typical FtsH proteins conserved domains. The expression level of GmFtsH9 was determined in a soybean recombinant inbred line population under a pot experiment conducted for measuring chlorophyll a fluorescence transient parameters, photosynthetic CO(2) fixation rate (P (N)), and seed yield. Expression quantitative trait loci (eQTL) mapping revealed two trans-acting eQTLs for GmFtsH9. The significant correlation of gene expression level with chlorophyll a fluorescence transient parameters and the presence of overlapping eQTL (QTL) between gene expression level and chlorophyll a fluorescence transient parameters indicated that GmFtsH9 could be involved in regulating PSII function. These results further lead to the understanding of the mechanism underlying FtsH gene expression, and contribute to the development of marker-assisted selection breeding programs for modulating soybean FtsH gene expression.

Genome-wide analysis of primary auxin-responsive Aux/IAA gene family in maize (Zea mays. L.).

The phytohormone auxin is important in various aspects of organism growth and development. Aux/IAA genes encoding short-lived nuclear proteins are responsive primarily to auxin induction. Despite their physiological importance, systematic analysis of Aux/IAA genes in maize have not yet been reported. In this paper, we presented the isolation and characterization of maize Aux/IAA genes in whole-genome scale. A total of 31 maize Aux/IAA genes (ZmIAA1 to ZmIAA31) were identified. ZmIAA genes are distributed in all the maize chromosomes except chromosome 2. Aux/IAA genes expand in the maize genome partly due to tandem and segmental duplication events. Multiple alignment and motif display results revealed major maize Aux/IAA proteins share all the four conserved domains. Phylogenetic analysis indicated Aux/IAA family can be divided into seven subfamilies. Putative cis-acting regulatory DNA elements involved in auxin response, light signaling transduction and abiotic stress adaption were observed in the promoters of ZmIAA genes. Expression data mining suggested maize Aux/IAA genes have temporal and spatial expression pattern. Collectively, these results will provide molecular insights into the auxin metabolism, transport and signaling research.

Genetic Mapping of the Leaf Number above the Primary Ear and Its Relationship with Plant Height and Flowering Time in Maize.

The leaf number above the primary ear (LA) is a major contributing factor to plant architecture in maize. The yield of leafy maize, which has extra LA compared to normal maize, is higher than normal maize in some regions. One major concern is that increasing LA may be accompanied by increased plant height and/or flowering time. Using an F2:3 population comprising 192 families derived from a leafy maize line and a normal maize line, an association population comprising 437 inbred maize lines, and a pair of near-isogenic maize lines, we mapped the quantitative trait loci (QTL) associated with LA and assessed its genetic relationship with flowering time and plant height. Ten QTL with an additive and dominant effect, 18 pairs of interacting QTL in the F2:3 population and seventeen significant SNPs in the association population were detected for LA. Two major QTL, qLA3-4 and qLA7-1, were repeatedly detected and explained a large proportion of the phenotypic variation. The qLA3-4 was centered on lfy1, which is a dominant gene underlying extra leaves above the ear in leafy maize. Four LA QTL were found to overlap with flowering time and/or plant height, which suggested that these QTL might have a pleiotropic effect. The pleiotropy of the lfy1 locus on LA, flowering time and plant height were validated by near-isogenic line analysis. These results enhance our understanding of the genetic architecture affecting maize LA and the development of maize hybrids with increased LA.

Ability to Remove Na+ and Retain K+ Correlates with Salt Tolerance in Two Maize Inbred Lines Seedlings.

Maize is moderately sensitive to salt stress; therefore, soil salinity is a serious threat to its production worldwide. Here, excellent salt-tolerant maize inbred line TL1317 and extremely salt-sensitive maize inbred line SL1303 were screened to understand the maize response to salt stress and its tolerance mechanisms. Relative water content, membrane stability index, stomatal conductance, chlorophyll content, maximum photochemical efficiency, photochemical efficiency, shoot and root fresh/dry weight, and proline and water soluble sugar content analyses were used to identify that the physiological effects of osmotic stress of salt stress were obvious and manifested at about 3 days after salt stress in maize. Moreover, the ion concentration of two maize inbred lines revealed that the salt-tolerant maize inbred line could maintain low Na+ concentration by accumulating Na+ in old leaves and gradually shedding them to exclude excessive Na+. Furthermore, the K+ uptake and retention abilities of roots were important in maintaining K+ homeostasis for salt tolerance in maize. RNA-seq and qPCR results revealed some Na+/H+ antiporter genes and Ca2+ transport genes were up-regulated faster and higher in TL1317 than those in SL1303. Some K+ transport genes were down-regulated in SL1303 but up-regulated in TL1317. RNA-seq results, along with the phenotype and physiological results, suggested that the salt-tolerant maize inbred line TL1317 possesses more rapidly and effectively responses to remove toxic Na+ ions and maintain K+ under salt stress than the salt-sensitive maize inbred line SL1303. This response should facilitate cell homoeostasis under salt stress and result in salt tolerance in TL1317.

Confirmation and Fine Mapping of a Major QTL for Aflatoxin Resistance in Maize Using a Combination of Linkage and Association Mapping.

Maize grain contamination with aflatoxin from Aspergillus flavus (A. flavus) is a serious health hazard to animals and humans. To map the quantitative trait loci (QTLs) associated with resistance to A. flavus, we employed a powerful approach that differs from previous methods in one important way: it combines the advantages of the genome-wide association analysis (GWAS) and traditional linkage mapping analysis. Linkage mapping was performed using 228 recombinant inbred lines (RILs), and a highly significant QTL that affected aflatoxin accumulation, qAA8, was mapped. This QTL spanned approximately 7 centi-Morgan (cM) on chromosome 8. The confidence interval was too large for positional cloning of the causal gene. To refine this QTL, GWAS was performed with 558,629 single nucleotide polymorphisms (SNPs) in an association population comprising 437 maize inbred lines. Twenty-five significantly associated SNPs were identified, most of which co-localised with qAA8 and explained 6.7% to 26.8% of the phenotypic variation observed. Based on the rapid linkage disequilibrium (LD) and the high density of SNPs in the association population, qAA8 was further localised to a smaller genomic region of approximately 1500 bp. A high-resolution map of the qAA8 region will be useful towards a marker-assisted selection (MAS) of A. flavus resistance and a characterisation of the causal gene.

Dense Stereo Matching Method Based on Local Affine Model.

A new method for constructing an accurate disparity space image and performing an efficient cost aggregation in stereo matching based on local affine model is proposed in this paper. The key algorithm includes a new self-adapting dissimilarity measurement used for calculating the matching cost and a local affine model used in cost aggregation stage. Different from the traditional region-based methods, which try to change the matching window size or to calculate an adaptive weight to do the aggregation, the proposed method focuses on obtaining the efficient and accurate local affine model to aggregate the cost volume while preserving the disparity discontinuity. Moreover, the local affine model can be extended to the color space. Experimental results demonstrate that the proposed method is able to provide subpixel precision disparity maps compared with some state-of-the-art stereo matching methods.

Gibberellin biosynthetic deficiency is responsible for maize dominant Dwarf11 (D11) mutant phenotype: physiological and transcriptomic evidence.

Dwarf stature is introduced to improve lodging resistance and harvest index in crop production. In many crops including maize, mining and application of novel dwarf genes are urgent to overcome genetic bottleneck and vulnerability during breeding improvement. Here we report the characterization and expression profiling analysis of a newly identified maize dwarf mutant Dwarf11 (D11). The D11 displays severely developmental abnormalities and is controlled by a dominant Mendelian factor. The D11 seedlings responds to both GA3 and paclobutrazol (PAC) application, suggesting that dwarf phenotype of D11 is caused by GA biosynthesis instead of GA signaling deficiency. In contrast, two well-characterized maize dominant dwarf plants D8 and D9 are all insensitive to exogenous GA3 stimulation. Additionally, sequence variation of D8 and D9 genes was not identified in the D11 mutant. Microarray and qRT-PCR analysis results demonstrated that transcripts encoding GA biosynthetic and catabolic enzymes ent-kaurenoic acid oxidase (KAO), GA 20-oxidase (GA20ox), and GA 2-oxidase (GA2ox) are up-regulated in D11. Our results lay a foundation for the following D11 gene cloning and functional characterization. Moreover, results presented here may aid in crops molecular improvement and breeding, especially breeding of crops with plant height ideotypes.