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Research Progress on Maize Dwarf Genes
LIJintao, SHEKuijun, WURui, YANGGuohu
Chin Agric Sci Bull ›› 2025, Vol. 41 ›› Issue (32) : 9-16.
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Abbreviation (ISO4): Chin Agric Sci Bull
Editor in chief: Yulong YIN
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Research Progress on Maize Dwarf Genes
Maize is the crop with the largest planting area in China, playing a crucial role in safeguarding national food security. Dwarfing breeding is a core approach to break the bottleneck of maize yield per unit area by optimizing plant architecture and increasing planting density. This paper systematically reviews the research progress on maize dwarf genes, with a focus on clarifying the biological significance of maize plant height traits, the practices of dwarf genetic breeding, and the regulatory mechanisms of plant hormones on plant height, while proposing future research directions. The results show that: (1) maize plant height is co-regulated by the number of internodes and internode length. Dwarf plants can reduce lodging risk by shortening internode length, optimize canopy structure, and improve light energy use efficiency and adaptability to dense planting, but it is necessary to coordinate the relationship between dwarfing and yield traits. (2) Maize dwarf genetics is divided into two major systems: single-gene and multi-gene. In the single-gene system, the br2 gene has the clearest molecular mechanism—it inhibits the elongation of stem cells, reducing stem length by 40% to 50% compared with the wild type, with a more significant effect on internodes below the ear position—and it is the most widely used major gene at present. The multi-gene system can avoid the defect of pleiotropy by accumulating minor-effect genes, and varieties such as 'Aidan 268' that balance dwarfing and high yield have been bred. (3) Gibberellin (GA), brassinosteroid (BR), and auxin (IAA) are the core hormones regulating plant height: mutations in GA synthesis-related genes (d1, an1) or signal genes (d8, d9) lead to dwarfing, loss of function of BR synthesis genes (brd1, na2) or signal genes (ZmBRI1a) causes stunted plants, and abnormal function of the IAA polar transport gene (br2) results in dwarfing of lower stem nodes. Currently, maize dwarf breeding has problems such as a relatively small number of applicable genes (more than 60 dwarf genes have been discovered, and about 40 have been cloned), genetic linkage drag restricting the coordination of traits, and insufficient functional verification of novel dwarf genes (such as the mapped genes K718d and d8227). In the future, it is necessary to explore medium dwarf genes suitable for dense planting, use genome-wide selection technology to aggregate multiple genes, and integrate phenomics with artificial intelligence to screen for ideal plant architecture, so as to breed maize varieties with the characters of dwarf stalks for lodging resistance, dense planting for high yield, wide adaptability and easy mechanical harvesting, and provide support for the sustainable development of the maize industry.
maize / plant height / dwarf gene / genetic breeding / plant hormone / plant height regulation / br2 gene
| [1] |
|
| [2] |
杨先冬, 刘伟, 曹利霞, 等. 展颖野生稻株高性状的遗传与SD1基因的等位变异分析[J]. 华北农学报, 2024, 39(1):18-26.
为了探究SSSL-B50和华粳籼74(HJX74)株高差异的原因,利用SSSL-B50与HJX74回交构建F<sub>2</sub>群体进行株高性状遗传分析与基因定位。结果显示,F<sub>1</sub>植株表现为高秆;260个单株组成的F<sub>2</sub>群体株高出现分离,高秆植株与半矮秆植株分离比例符合3:1(χ<sup>2</sup>=0.18<3.84),说明SSSL-B50高秆性状为显性性状,受1对显性等位基因控制。利用IciMapping软件对F<sub>2</sub>进行连锁分析,将SSSL-B50携带的高秆基因定位在1号染色体代换片段上的标记S18和X161之间38.38~39.07 Mb。候选基因筛选分析发现,定位区间内存在着“绿色革命”基因座位SD1。对展颖野生稻、SSSL-B50及HJX74进行SD1基因测序及序列比对,发现HJX74的CDS序列与展颖野生稻、SSSL-B50相比有280 bp的缺失,导致氨基酸编码提前终止。qRT-PCR结果表明,SD1表达量在SSSL-B50茎秆的第2,3,4节均显著高于HJX74。此外,与前人报道结果相比,展颖野生稻SD1基因编码的氨基酸序列发生了2处改变(E100G、Q339R)。研究结果弄清楚了展颖野生稻单片段代换系SSSL-B50高秆性状受SD1调控,同时从展颖野生稻鉴定到了SD1的新等位型SD1<sup>Glu</sup>。
|
| [3] |
丁梦云, 刘天相, 孙宇慧, 等. 小麦QTL富集区QC-4BS重要农艺性状基因的精细定位及Rht1基因的效应分析[J]. 麦类作物学报, 2018, 38(3):262-267.
|
| [4] |
|
| [5] |
王宝宝, 王海洋. 理想株型塑造之于玉米耐密改良[J]. 生物技术通报, 2023, 39(8):11-30.
玉米是生产能力最强的谷物作物，其充足稳定供给对保证世界范围内的粮食安全至关重要。长期的研究和生产实践表明，提高品种耐密性和种植密度是提高玉米产量的关键，而塑造理想的株型是提高玉米耐密性的重要途径。报道显示紧凑的叶夹角、较低的穗位高、较少的雄穗分枝数、较早的开花期，是玉米耐密株型性状的重要组成部分。本文从这4类性状入手，对其与耐密性的关系、形态发育及遗传调控基础的研究进展进行综述，并通过对目前研究的分析，提出了未来玉米耐密株型改良研究的一些方向，期望能为未来的玉米耐密育种提供一些有用的借鉴。
|
| [6] |
凌莉, 裴文东. 种植密度对不同熟期玉米茎秆抗倒伏特性及产量的影响[J]. 玉米科学, 2024, 32(2):106-113.
|
| [7] |
阎淑琴. 矮生玉米的遗传与育种[J]. 玉米科学, 2000(2):36-37,45.
|
| [8] |
张贺通. 玉米株高基因ZmDLE1的精细定位[D]. 武汉: 华中农业大学, 2022.
|
| [9] |
|
| [10] |
慈晓科, 郝玉波, 张吉旺, 等. 不同产量水平的玉米自交系农艺性状分析[J]. 玉米科学, 2010, 18(3):25-30,36.
|
| [11] |
杨梅. 玉米株高QTL qPH3.2和qPH3.3的精细定位[D]. 武汉: 华中农业大学, 2017.
|
| [12] |
石云素, 于永涛, 宋燕春, 等. 一个新矮生玉米种质资源的发现与遗传鉴定[J]. 植物遗传资源学报, 2008, 9(4):521-524.
|
| [13] |
王天依, 王荣焕, 王夏青, 等. 玉米矮秆基因与矮秆育种研究[J]. 生物技术通报, 2023, 39(8):43-51.
株高是影响玉米株型和种植密度的重要农艺性状，培育耐密植的矮秆/半矮秆新品种可为增产做贡献。但目前多数矮秆突变体单株产量损失较大，难以在育种中应用。因此，探究玉米株高的调控机制、挖掘株高基因的优良等位变异，从而改善玉米株型结构、提高群体光能利用率、增强群体对水肥的耐性，对提高玉米产量尤为重要。本文综述了目前挖掘到的株高数量性状位点，阐述了株高相关基因主要受植物激素、微管结合蛋白以及成花因子调节；概述了Brachytic2（Br2）基因在玉米矮秆育种研究中的应用及其局限性；最后展望了矮秆有利等位基因及其分子标记和现代生物技术在矮秆种质资源创制中的重要价值。本文将为玉米株高的遗传机制解析以及矮秆玉米分子育种奠定基础。
|
| [14] |
杨永生. 南矮一号玉米试种表现及栽培要点[J]. 新疆农业科学, 1981(3):11-12.
|
| [15] |
田齐建, 乔治军, 董存吉, 等. 玉米矮化育种研究进展及发展前景[J]. 山西农业科学, 2003(2):23-26.
|
| [16] |
崔绍平. 玉米br-2矮生基因型杂交种矮单268的选育[J]. 中国种业, 2014(12):68-69.
|
| [17] |
吴涛, 崔绍平. 矮单268玉米的选育概况及栽培技术[J]. 现代农村科技, 2016(7):17.
|
| [18] |
董丽, 石海春, 赵长云, 等. 玉米矮秆突变体K718d的遗传鉴定[J]. 华北农学报, 2021, 36(6):71-77.
发掘新的玉米矮秆资源，并研究其遗传特性，可为玉米矮化育种提供新的物质基础。以自然突变获得的矮秆突变体K718d和野生型K718为材料，比较表型差异和对外源激素的敏感性；K718d与5个高秆自交系组配正反交F<sub>1</sub>、BC<sub>1</sub>、BC<sub>2</sub>和F<sub>2</sub>群体，分析矮秆性状的遗传模式，通过BSA-SSR标记法定位矮秆基因，用等位杂交法鉴定基因的等位性。结果表明，与K718相比，K718d株高、穗位高、节间数和节间长度分别降低48.23%，75.57%，30.83%和65.92%，穗长缩短28.57%，产量降低36.44%，差异均达极显著水平；突变体K718d对GA<sub>3</sub>和IAA均不敏感。2个生态点试验结果，正反交F<sub>1</sub>均为高秆；BC<sub>1</sub>和F<sub>2</sub>群体高矮秆植株分离比例分别符合1：1和3：1，BC<sub>2</sub>群体为高秆，表明K718d株高由1对隐性细胞核基因控制。将矮秆基因d718定位于1号染色体SSR标记umc2569 和umc1278之间，遗传距离分别为1.0，2.5 cM，是一个br1等位基因。该结果为d718的进一步精细定位和克隆奠定了基础。
|
| [19] |
唐兰, 李若楠, 吴元奇. 矮秆玉米d8227的矮化机理及基因精细定位[J]. 玉米科学, 2025, 33(1):22-30.
|
| [20] |
|
| [21] |
王立静, 哈丽旦, 张素梅, 等. 新的玉米矮秆突变基因的鉴定与遗传分析[J]. 华北农学报, 2008(5):23-25.
Dt基因是玉米显性矮秆基因，被定位于玉米的第10条染色体长臂，目前报道的显性矮秆基因只有D8(Mpl1)和D9，它们分别位于染色体1的长臂和染色体5的短臂；Dt矮秆突变体属于赤霉素敏感型，含有D8，D9基因的材料对赤霉素不敏感；Dt基因与D8，D9基因的等位性分析表明，Dt与D8，D9为非等位基因，进一步证明了Dt基因是一个新发现的玉米显性矮秆基因。
|
| [22] |
|
| [23] |
姜惟廉, 郭日跻, 刘元芝, 等. 玉米优异核心种质资源多基因矮生系5003及其姊妹系5005创制[J]. 玉米科学, 2013, 21(5):1-5,12.
|
| [24] |
|
| [25] |
|
| [26] |
|
| [27] |
|
| [28] |
|
| [29] |
|
| [30] |
|
| [31] |
The d2003 is a natural dwarf mutant from maize inbred line K36 and has less than one-third of K36 plant height with severely shortened internodes. In this study, we reported the cloning of d2003 gene using positional cloning. The results showed that there was a single-base insertion in the coding region of Viviparous8 (VP8) in d2003 mutant, which resulted in a premature stop codon. Further genetic allelism tests confirmed that d2003 mutation is a novel allele of VP8. VP8 is mainly expressed in the stem apex, young leaves, and developing vascular tissues, and its expression levels in nodes are significantly higher than that in internodes at 12-leaf stage. Subcellular localization demonstrated that the VP8 protein is localized to the endoplasmic reticulum and the N-terminal 26 amino acids (aa) of VP8 protein are essential to its localization in ER. Further transgenic experiments showed that lack of the 26 aa leads to loss of VP8 function in Arabidopsis amp1 phenotype rescue. These results strongly suggested that the N-terminal 26 aa is critical for VP8 protein localization, and the correct protein localization of VP8 in ER is necessary for its function.
|
| [32] |
|
| [33] |
Blade cutters are a component in paddy field pulping machines that perform mud splashing, and the design of their structural and motion parameters will directly affect the splashed-mud volume and pulping-machine efficiency. Therefore, the optimization of the blade cutter’s structural and motion parameters is an important approach for improving the operating performance of paddy field pulping machines. In this study, based on the central-composite-design (CCD) method and a response-surface-method-based variance analysis, a regression-forecast model for the relationship between the splashing performance of the blade cutter and the blade’s structural and motion parameters was constructed to determine the influence of these parameters on the multi-dimensional splashing performance of blade cutters. Additionally, with the construction of a multi-objective performance-optimization model for pulping-machine blade cutters, the predicted optimal structural and motion parameters could be obtained based on the genetic algorithm. The ideal operating performance could be achieved when the blade turning radius was 180 mm, with a bending angle of 125°, a sub-cutter dip angle of 63°, a forward velocity of 0.15 m/s, and a rotating speed of 158 r/min. Verification of the optimization results in a bench test showed that the mean relative errors between the theoretical and experimental values of the mud volume and power consumption were 9.13% and 8.86%, respectively, revealing the high accuracy of the mud-volume and power-consumption models. Furthermore, there was a significant reduction in blade-cutter unit power consumption of 19.13%. These research results can provide a theoretical reference and technical support for blade-cutter optimization and improving pulping-machine performance.
|
| [34] |
|
| [35] |
Brassinosteroids represent a class of plant hormones with high-growth promoting activity. They are found at low levels in pollen, anthers, seeds, leaves, stems, roots, flowers, grain, and young vegetative tissues throughout the plant kingdom. Brassinosteroids are a family of about 60 phytosteroids. The article gives a comprehensive survey on the hitherto known brassinosteroids isolated from plants. The chemical characteristic of brassinosteroids is also presented.
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| [36] |
Brassinosteroids (BRs) are plant hormones involved in many developmental processes as well as in plant-environment interactions. Their role was investigated in this study through the analysis of lilliputian1-1 (lil1-1), a dwarf mutant impaired in BR biosynthesis in maize (Zea mays).We isolated lil1-1 through transposon tagging in maize. The action of lil1 was investigated through morphological and genetic analysis. Moreover, by comparing lil1-1 mutant and wild-type individuals grown under drought stress, the effect of BR reduction on the response to drought stress was examined.lil1-1 is a novel allele of the brassinosteroid-deficient dwarf1 (brd1) gene, encoding a brassinosteroid C-6 oxidase. We show in this study that lil1 is epistatic to nana plant1 (na1), a BR gene involved in earlier steps of the pathway. The lill-1 mutation causes alteration in the root gravitropic response, leaf epidermal cell density, epicuticular wax deposition and seedling adaptation to water scarcity conditions.Lack of active BR molecules in maize causes a pleiotropic effect on plant development and improves seedling tolerance of drought. BR-deficient maize mutants can thus be instrumental in unravelling novel mechanisms on which plant adaptations to abiotic stress are based.
|
| [37] |
Structural variation in plant genomes is a significant driver of phenotypic variability in traits important for the domestication and productivity of crop species. Among these are traits that depend on functional meristems, populations of stem cells maintained by the CLAVATA-WUSCHEL (CLV-WUS) negative feedback-loop that controls the expression of the WUS homeobox transcription factor. WUS function and impact on maize development and yield remain largely unexplored. Here we show that the maize dominant Barren inflorescence3 (Bif3) mutant harbors a tandem duplicated copy of the ZmWUS1 gene, ZmWUS1-B, whose novel promoter enhances transcription in a ring-like pattern. Overexpression of ZmWUS1-B is due to multimerized binding sites for type-B RESPONSE REGULATORs (RRs), key transcription factors in cytokinin signaling. Hypersensitivity to cytokinin causes stem cell overproliferation and major rearrangements of Bif3 inflorescence meristems, leading to the formation of ball-shaped ears and severely affecting productivity. These findings establish ZmWUS1 as an essential meristem size regulator in maize and highlight the striking effect of cis-regulatory variation on a key developmental program.
|
| [38] |
The maize (Zea mays) gibberellin (GA)-deficient mutant dwarf1 (d1) displays dwarfism and andromonoecy (i.e. forming anthers in the female flower). Previous characterization indicated that the d1 mutation blocked three steps in GA biosynthesis; however, the locus has not been isolated and characterized. Here, we report that D1 encodes a GA 3-oxidase catalyzing the final step of bioactive GA synthesis. Recombinant D1 is capable of converting GA20 to GA1, GA20 to GA3, GA5 to GA3, and GA9 to GA4 in vitro. These reactions are widely believed to take place in the cytosol. However, both in vivo GFP fusion analysis and western-blot analysis of organelle fractions using a D1-specific antibody revealed that the D1 protein is dual localized in the nucleus and cytosol. Furthermore, the upstream gibberellin 20-oxidase1 (ZmGA20ox1) protein was found dual localized in the nucleus and cytosol as well. These results indicate that bioactive GA can be synthesized in the cytosol and the nucleus, two compartments where GA receptor Gibberellin-insensitive dwarf protein1 exists. Furthermore, the D1 protein was found to be specifically expressed in the stamen primordia in the female floret, suggesting that the suppression of stamen development is mediated by locally synthesized GAs. © 2014 American Society of Plant Biologists. All Rights Reserved.
|
| [39] |
Brassinosteroids (BRs) are plant hormones that regulate growth and development. They share structural similarities with animal steroids, which are decisive factors of sex determination. BRs are known to regulate morphogenesis and environmental stress responses, but their involvement in sex determination in plants has been only speculative. We show that BRs control sex determination in maize revealed through characterization of the classical dwarf mutant nana plant1 (na1), which also feminizes male flowers. na1 plants carry a loss-of-function mutation in a DET2 homolog--a gene in the BR biosynthetic pathway. The mutant accumulates the DET2-specific substrate (24R)-24-methylcholest-4-en-3-one with a concomitant decrease of downstream BR metabolites. Treatment of wild-type maize plants with BR biosynthesis inhibitors completely mimicked both dwarf and tasselseed phenotypes of na1 mutants. Tissue-specific na1 expression in anthers throughout their development supports the hypothesis that BRs promote masculinity of the male inflorescence. These findings suggest that, in the monoecious plant maize, BRs have been coopted to perform a sex determination function not found in plants with bisexual flowers.
|
| [40] |
|
| [41] |
戚洪源, 李卫华, 付志远, 等. 玉米隐性矮秆突变体的遗传分析与初步定位[J]. 河南农业大学学报, 2013, 47(3):245-249.
|
| [42] |
|
| [43] |
|
| [44] |
|
| [45] |
Development in higher plants depends on the activity of meristems,formative regions that continuously initiate new organs at their flanks. Meristems must maintain a balance between stem cell renewal and organ initiation. In fasciated mutants, organ initiation fails to keep pace with meristem proliferation. The thick tassel dwarf1 (td1)mutation of maize affects both male and female inflorescence development. The female inflorescence, which results in the ear, is fasciated, with extra rows of kernels. The male inflorescence, or tassel, shows an increase in spikelet density. Floral meristems are also affected in td1 mutants; for example, male florets have an increase in stamen number. These results suggest that td1 functions in the inflorescence to limit meristem size. In addition, td1 mutants are slightly shorter than normal siblings,indicating that td1 also plays a role in vegetative development. td1 encodes a leucine-rich repeat receptor-like kinase (LRR-RLK) that is a putative ortholog of the Arabidopsis CLAVATA1 protein. These results complement previous work showing that fasciated ear2 encodes a CLAVATA2-like protein, and suggest that the CLAVATA signaling pathway is conserved in monocots. td1 maps in the vicinity of quantitative trait loci that affect seed row number, spikelet density and plant height. We discuss the possible selection pressures on td1 during maize domestication.
|
| [46] |
In maize (Zea mays L.), as in other grass species, stem elongation occurs during growth and most noticeably upon the transition to flowering. Genes that reduce stem elongation have been important to reduce stem breakage, or lodging. Stem elongation has been mediated by dwarf and brachytic/brevis plant mutants that affect giberellic acid and auxin pathways, respectively. Maize brevis plant1 (bv1) mutants, first identified over 80 years ago, strongly resemble brachytic2 mutants that have shortened internodes, short internode cells, and are deficient in auxin transport. Here, we characterized two novel bv1 maize mutants. We found that an inositol polyphosphate 5-phosphatase orthologue of the rice gene dwarf50 was the molecular basis for the bv1 phenotype, implicating auxin-mediated inositol polyphosphate and/or phosphoinositide signalling in stem elongation. We suggest that auxin-mediated internode elongation involves processes that also contribute to stem gravitropism. Genes misregulated in bv1 mutants included genes important for cell wall synthesis, transmembrane transport, and cytoskeletal function. Mutant and wild-type plants were indistinguishable early in development, responded similarly to changes in light quality, had unaltered flowering times, and had normal flower development. These attributes suggest that breeding could utilize bv1 alleles to increase crop grain yields.© The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.
|
| [47] |
|
| [48] |
Auxin plays a fundamental role in organogenesis in plants. Multiple pathways for auxin biosynthesis have been proposed, but none of the predicted pathways are completely understood. Here, we report the positional cloning and characterization of the vanishing tassel2 (vt2) gene of maize (Zea mays). Phylogenetic analyses indicate that vt2 is a co-ortholog of TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS1 (TAA1), which converts Trp to indole-3-pyruvic acid in one of four hypothesized Trp-dependent auxin biosynthesis pathways. Unlike single mutations in TAA1, which cause subtle morphological phenotypes in Arabidopsis thaliana, vt2 mutants have dramatic effects on vegetative and reproductive development. vt2 mutants share many similarities with sparse inflorescence1 (spi1) mutants in maize. spi1 is proposed to encode an enzyme in the tryptamine pathway for Trp-dependent auxin biosynthesis, although this biochemical activity has recently been questioned. Surprisingly, spi1 vt2 double mutants had only a slightly more severe phenotype than vt2 single mutants. Furthermore, both spi1 and vt2 single mutants exhibited a reduction in free auxin levels, but the spi1 vt2 double mutants did not have a further reduction compared with vt2 single mutants. Therefore, both spi1 and vt2 function in auxin biosynthesis in maize, possibly in the same pathway rather than independently as previously proposed.
|
| [49] |
|
| [50] |
The maize crinkly4 (cr4) mutation affects leaf epidermis differentiation such that cell size and morphology are altered, and surface functions are compromised, allowing graft-like fusions between organs. In the seed, loss of cr4 inhibits aleurone formation in a pattern that reflects the normal progression of differentiation over the developing endosperm surface. The cr4 gene was isolated by transposon tagging and found to encode a putative receptor kinase. The extracellular domain contains a cysteine-rich region similar to the ligand binding domain in mammalian tumor necrosis factor receptors (TNFRs) and seven copies of a previously unknown 39-amino acid repeat. The results suggest a role for cr4 in a differentiation signal.
|
| [51] |
李启芳, 王立静, 商伟, 等. 玉米矮秆突变体52333Dt降秆机制的初步研究[J]. 山东农业科学, 2010(10):24-26.
|
| [52] |
|
| [53] |
刘洁, 李润植. 作物矮化基因与GA信号转导途径[J]. 中国农学通报, 2005(1):37-40,52.
|
| [54] |
Bioactive gibberellins (GAs) are tetracyclic diterpenoid plant hormones that promote important processes of plant growth and development, such as seed germination, growth through elongation, and floral transition. Thus, mutant plants that are affected in GA biosynthesis or signalling exhibit altered seed germination and, at the adult stage, are dwarf and dark green and also show delayed flowering. The components of the GA metabolism and signalling pathways are reviewed here and recent findings regarding the regulation and possible mode of action of DELLA proteins are discussed.
|
| [55] |
Bacteriophages have been proposed as an alternative to pesticides to kill bacterial pathogens of crops. However, the efficacy of phage biocontrol is variable and poorly understood in natural rhizosphere microbiomes. We studied biocontrol efficacy of different phage combinations on Ralstonia solanacearum infection in tomato. Increasing the number of phages in combinations decreased the incidence of disease by up to 80% in greenhouse and field experiments during a single crop season. The decreased incidence of disease was explained by a reduction in pathogen density and the selection for phage-resistant but slow-growing pathogen strains, together with enrichment for bacterial species that were antagonistic toward R. solanacearum. Phage treatment did not affect the existing rhizosphere microbiota. Specific phage combinations have potential as precision tools to control plant pathogenic bacteria.
|
| [56] |
The data presented here show that, in cultures of type 1 astrocytes obtained from the hypothalamus of neonatal female rat, 17β‐oestradiol is able to increase both the mRNA and the protein levels of basic fibroblast growth factor (bFGF). In particular, after 24 h of exposure to 17β‐oestradiol (10−9 and 10−10 m), an increase of messenger levels of bFGF appears in hypothalamic type 1 astrocytes. Similarly, an induction of bFGF protein is also evident at this time of exposure. The effect on the mRNA and protein levels of bFGF is blocked by the presence in the medium of an antibody raised against the transforming growth factor α (TGFα) receptor. This observation indicates that, TGFα, whose synthesis is modulated by oestrogens in hypothalamic astrocytes and which is able to increase, both the mRNA and the protein levels of bFGF in our experimental model, may act as the mediator of the oestrogenic induction of bFGF. Hypothalamic astrocytes, together with hypothalamic neurones synthesizing and secreting luteinizing hormone‐releasing hormone (LHRH), form the LHRH network in conjunction with other neuronal systems. Gonadal steroids in general, and oestrogens in particular, play an important role in the control of the activity of this network. In addition, bFGF and TGFα, two growth factors released from astrocytes, are able to influence the activity of LHRH neurones. The present observations suggest that oestrogens may also act on LHRH neurones in an indirect fashion (i.e. by modulating the expression of bFGF and TGFα in glial cells).
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| [57] |
Gibberellic acid (GA) promotes seed germination, elongation growth, and flowering time in plants. GA responses are repressed by DELLA proteins, which contain an N-terminal DELLA domain essential for GA-dependent proteasomal degradation of DELLA repressors. Mutations of or within the DELLA domain of DELLA repressors have been described for species including Arabidopsis thaliana, wheat (Triticum aestivum), maize (Zea mays), and barley (Hordeum vulgare), and we show that these mutations confer GA insensitivity when introduced into the Arabidopsis GA INSENSITIVE (GAI) DELLA repressor. We also demonstrate that Arabidopsis mutants lacking the three GA INSENSITIVE DWARF1 (GID1) GA receptor genes are GA insensitive with respect to GA-promoted growth responses, GA-promoted DELLA repressor degradation, and GA-regulated gene expression. Our genetic interaction studies indicate that GAI and its close homolog REPRESSOR OF ga1-3 are the major growth repressors in a GA receptor mutant background. We further demonstrate that the GA insensitivity of the GAI DELLA domain mutants is explained in all cases by the inability of the mutant proteins to interact with the GID1A GA receptor. Since we found that the GAI DELLA domain alone can mediate GA-dependent GID1A interactions, we propose that the DELLA domain functions as a receiver domain for activated GA receptors.
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| [58] |
We investigated the physiological function of three Arabidopsis thaliana homologs of the gibberellin (GA) receptor GIBBERELLIN-INSENSITIVE DWARF1 (GID1) by determining the developmental consequences of GID1 inactivation in insertion mutants. Although single mutants developed normally, gid1a gid1c and gid1a gid1b displayed reduced stem height and lower male fertility, respectively, indicating some functional specificity. The triple mutant displayed a dwarf phenotype more severe than that of the extreme GA-deficient mutant ga1-3. Flower formation occurred in long days but was delayed, with severe defects in floral organ development. The triple mutant did not respond to applied GA. All three GID1 homologs were expressed in most tissues throughout development but differed in expression level. GA treatment reduced transcript abundance for all three GID1 genes, suggesting feedback regulation. The DELLA protein REPRESSOR OF ga1-3 (RGA) accumulated in the triple mutant, whose phenotype could be partially rescued by loss of RGA function. Yeast two-hybrid and in vitro pull-down assays confirmed that GA enhances the interaction between GID1 and DELLA proteins. In addition, the N-terminal sequence containing the DELLA domain is necessary for GID1 binding. Furthermore, yeast three-hybrid assays showed that the GA-GID1 complex promotes the interaction between RGA and the F-box protein SLY1, a component of the SCFSLY1 E3 ubiquitin ligase that targets the DELLA protein for degradation.
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| [59] |
<p>Brassinosteroids (BRs) are a group of naturally-occurring steroidal phytohormones playing fundamental roles during normal plant growth and development. Using a combination of experimental approaches, including analytical chemistry, genetics, and biochemistry, the major BR biosynthetic pathway has been largely elucidated. The least-understood knowledge in the BR research field is probably the molecular mechanisms controlling the bioactive levels of BRs in response to various developmental and environmental cues. In this review, we focus our discussion on a recently-proposed, 8-step predominant BR biosynthetic pathway, several newly-identified transcription factors regulating the expression of key enzymes that catalyze BR biosynthesis, and up-to-date information about the mechanisms that plants use to inactivate unnecessary BRs.</p><p><strong>Zhao B, Li J</strong> (2012) Regulation of brassinosteroid biosynthesis and inactivation. <em>J. Integr. Plant Biol</em>. <strong>54</strong>(10), 746–759.</p>
|
| [60] |
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| [61] |
Brassinosteroids (BRs) are plant hormones involved in various growth and developmental processes. The BR signaling system is well established in Arabidopsis (Arabidopsis thaliana) and rice (Oryza sativa) but poorly understood in maize (Zea mays). BRASSINOSTEROID INSENSITIVE1 (BRI1) is a BR receptor, and database searches and additional genomic sequencing identified five maize homologs including duplicate copies of BRI1 itself. RNA interference (RNAi) using the extracellular coding region of a maize zmbri1 complementary DNA knocked down the expression of all five homologs. Decreased response to exogenously applied brassinolide and altered BR marker gene expression demonstrate that zmbri1-RNAi transgenic lines have compromised BR signaling. zmbri1-RNAi plants showed dwarf stature due to shortened internodes, with upper internodes most strongly affected. Leaves of zmbri1-RNAi plants are dark green, upright, and twisted, with decreased auricle formation. Kinematic analysis showed that decreased cell division and cell elongation both contributed to the shortened leaves. A BRASSINOSTEROID INSENSITIVE1-ETHYL METHANESULFONATE-SUPPRESSOR1-yellow fluorescent protein (BES1-YFP) transgenic line was developed that showed BR-inducible BES1-YFP accumulation in the nucleus, which was decreased in zmbri1-RNAi. Expression of the BES1-YFP reporter was strong in the auricle region of developing leaves, suggesting that localized BR signaling is involved in promoting auricle development, consistent with the zmbri1-RNAi phenotype. The blade-sheath boundary disruption, shorter ligule, and disrupted auricle morphology of RNAi lines resemble KNOTTED1-LIKE HOMEOBOX (KNOX) mutants, consistent with a mechanistic connection between KNOX genes and BR signaling. © 2015 American Society of Plant Biologists. All Rights Reserved.
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| [62] |
\n Agriculturally advantageous reduction in plant height is usually achieved by blocking the action or production of gibberellins. Here, we describe a different dwarfing mechanism found in maize\n brachytic2\n (\n br2\n ) mutants characterized by compact lower stalk internodes. The height reduction in these plants results from the loss of a P-glycoprotein that modulates polar auxin transport in the maize stalk. The sorghum ortholog of\n br2\n is\n dwarf3\n (\n dw3\n ), an unstable mutant of long-standing commercial interest and concern. A direct duplication within the\n dw3\n gene is responsible for its mutant nature and also for its instability, because it facilitates unequal crossing-over at the locus.\n
|
| [63] |
|
| [64] |
|
| [65] |
王晓雯, 王媛媛, 冯蓓祺, 等. 水稻矮化多蘖突变体mtd2/htd1-1的鉴定与图位克隆[J]. 西南大学学报(自然科学版), 2024, 46(2):2-12.
|
| [66] |
|
| [67] |
|
| [68] |
唐兰, 吴元奇. 玉米矮秆基因及调控机理的研究进展[J]. 北方农业学报, 2023, 51(5):23-30.
株高是玉米理想株型的重要指标，与产量密切相关，影响着植物光合利用率、抗倒伏性、收获指数等。植物激素通过影响细胞的分裂和伸长来改变玉米的节间长度和数目，从而调节玉米高度达到矮化的效果。文章综述了近年来控制玉米株高的QTL/基因定位和克隆的研究进展以及激素（GA<sub>3</sub>、IAA、BR）调控下矮化突变体的形成，以期为玉米育种生产和应用提供参考。
|
| [69] |
王文秀, 王磊. 玉米矮秆基因研究进展[J]. 生物技术通报, 2018, 34(11):22-26.
玉米已成为我国种植面积最大的农作物,提高玉米的种植密度是提高玉米产量的重要技术手段。玉米的株型改良成为玉米遗传育种研究的重点之一。合理株型和抗倒伏能力是影响玉米产量的重要农艺性状,也是衡量优良玉米品种的重要指标之一。通过玉米矮化基因的分离及研究,开发相应的分子标记,培育出矮化或半矮化玉米植株,从而改善玉米株型结构,增加种植密度,提高群体光合效能,提高玉米产量。主要从玉米矮化育种的概况、玉米矮化基因遗传特点、玉米矮化基因的表型以及激素对玉米矮化的影响等方面的研究进行了总结和概述,为玉米矮化基因的开发利用及分子机制的阐明提供新的信息。
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