Controlling Plant Height Research Articles

Novel Allelic Mutations in Dw3 Gene That Affect the Height of Sorghum Plants.

Breeding for dwarfing traits in sorghum is crucial. However, only three genes (Dw1-Dw3) that control plant height have been mapped. In this study, 634 sorghum cultivars were collected to investigate plant height and genotypes. Four were genotyped Dw1DW2Dw3 (wild type) but with different plant heights, and they were selected to construct two populations and map new dwarf genes. Bulked segregant analysis with whole-genome resequencing of the two populations identified the candidate gene in one same genomic region-on chromosome 7. Then, it was narrowed down to a region containing nine genes. Amino acid and DNA sequence analysis of the parent and offspring plants revealed that two novel allelic mutations in the Dw3 gene play a role in reducing the plant height-8R262 or 8R417, including 1 bp substitution and 2 bp deletions. Furthermore, we sequenced 19 cultivars that primarily exhibited a "one-dwarf" hybrid or wild-type and presumed another allelic mutation via the amino acid alignment of 8R019, 8R100, and 8R402, which was another one-base substitution. These results indicate that multiple types of allelic mutations in the Dw3 gene should be considered when identified or applied.

Tomato SlARF5 participate in the flower organ initiation process and control plant height

Plant height is a critical agronomic trait closely linked to yield, primarily regulated by Gibberellins (GA) and auxins, which interact in complex ways. However, the mechanism underlying their interactions remain incompletely understood. In this study, we identified a tomato mutant exhibiting significantly reduced plant height. Through gene cloning and bulked segregant analysis (BSA) sequencing, we found that the mutant gene corresponds to the tomato auxin response factor gene SlARF5/MP. Here, we show that overexpression of SlARF5/MP significantly enhances plant height. Additionally, treatment with GA3 restored the plant height of the mutant to wild-type (WT) levels, indicating that GA content is a key factor influencing plant height. We also observed significant upregulation of GA-biosynthesis genes, including GA2-oxidases GA20ox3 and GA20ox4, as well as the GA3 biosynthesis gene GA3ox1, in SlARF5-overexpressing plants. Furthermore, we demonstrated that SlARF5 directly binds to SlGA2ox3, which mediates the conversion of GA3 to inactive GA, therebyregulating its expression. Our findings suggest that SlARF5 modulates GA3 metabolism by regulating GA synthesis genes, ultimately leading to alterations in plant height.

Sprouting and Growth of Garlic (Allium sativum L.) At Green Stage Under Various Nutrients.

Garlic (Allium sativum L.) is a vital crop, yet its growth and sprouting at the green stage can be significantly influenced by nutrient availability, which poses a challenge for optimizing yield and quality. The present research was carried out in 2022–2023 at the Nursery Department of Horticulture, Sindh Agriculture University Tandojam, to assess the sprouting and growth of garlic (Allium sativum L.) at green stage under various nutrients. The experimental trial was carried out in complete randomization (CRD) with three replications. Two varieties, a Chinese and a local (Desi) (Desi) variety, were grown in the pots. Macronutrients used as treatments included N1 (control). N2 = NPK+TE (trace elements) 2 g, L-1. N3 = Calcium Nitrate 0.5g, L-1 and N4 = NPK+TE 2g, L-1 + Calcium Nitrate 0.5g, L-1. The results of the present studies showed a statistically significant difference for treatments and nutrient combinations. Best results for all observations were noted in plants supplied with NPK+TE 2g L-1 that had maximum plant height 55.83 cm, leaves plant-1 6.83, leaf length 47.66 cm, leaf weight 8.96g, plant weight 13.20g, neck thickness 6.55mm, root weight 2.68g, and root depth 19.83cm. Fallow control plant height 41.00cm leaves plant-1 5.00, leaf length 31.00cm, leaves weight 4.73g, plant weight 7.61g, neck thickness 3.51mm, root weight 1.46g and root depth 12.00cm. In between varieties the Chinese had maximum plant height 54.66cm, leaves plant-1 7.00, leaf length 45.00cm, leaves weight 10.04g, plant weight 10.99g, neck thickness 8.26mm, root weight 2.81g and root depth 22.00cm. Based on nutrients, the Chinese variety of garlic performed better growth at the green stage than the local (Desi) variety of garlic. The findings of this study show that nutrient N2 = NPK+TE (Trace Elements) 2g L-1had better results for all parameters, and all results were statistically significant.

Exploring Novel Genomic Loci and Candidate Genes Associated with Plant Height in Bulgarian Bread Wheat via Multi-Model GWAS.

In the context of crop breeding, plant height (PH) plays a pivotal role in determining straw and grain yield. Although extensive research has explored the genetic control of PH in wheat, there remains an opportunity for further advancements by integrating genomics with growth-related phenomics. Our study utilizes the latest genome-wide association scan (GWAS) techniques to unravel the genetic basis of temporal variation in PH across 179 Bulgarian bread wheat accessions, including landraces, tall historical, and semi-dwarf modern varieties. A GWAS was performed with phenotypic data from three growing seasons, the calculated best linear unbiased estimators, and the leveraging genotypic information from the 25K Infinium iSelect array, using three statistical methods (MLM, FarmCPU, and BLINK). Twenty-five quantitative trait loci (QTL) associated with PH were identified across fourteen chromosomes, encompassing 21 environmentally stable quantitative trait nucleotides (QTNs), and four haplotype blocks. Certain loci (17) on chromosomes 1A, 1B, 1D, 2A, 2D, 3A, 3B, 4A, 5B, 5D, and 6A remain unlinked to any known Rht (Reduced height) genes, QTL, or GWAS loci associated with PH, and represent novel regions of potential breeding significance. Notably, these loci exhibit varying effects on PH, contribute significantly to natural variance, and are expressed during seedling to reproductive stages. The haplotype block on chromosome 6A contains five QTN loci associated with reduced height and two loci promoting height. This configuration suggests a substantial impact on natural variation and holds promise for accurate marker-assisted selection. The potentially novel genomic regions harbor putative candidate gene coding for glutamine synthetase, gibberellin 2-oxidase, auxin response factor, ethylene-responsive transcription factor, and nitric oxide synthase; cell cycle-related genes, encoding cyclin, regulator of chromosome condensation (RCC1) protein, katanin p60 ATPase-containing subunit, and expansins; genes implicated in stem mechanical strength and defense mechanisms, as well as gene regulators such as transcription factors and protein kinases. These findings enrich the pool of semi-dwarfing gene resources, providing the potential to further optimize PH, improve lodging resistance, and achieve higher grain yields in bread wheat.

Expression of TAD1 (Tillering & Dwarf1) Gene in Hawara Bunar and IR64 Rice Cultivars

Rice cv. Hawara Bunar is a local rice cultivar tolerant to aluminum (Al) and drought stress. However, the cultivar has inferior characteristics, such as a tall habitus and a small number of tillers, making the cultivar agronomically unattractive. Many genes control plant height and tiller number; one is the TAD1 gene. Analysis of gene expression in two contrasting rice cultivars for both characters is a prerequisite for selecting certain genes for gene editing targets. This study aimed to analyze the gene expression of the TAD1 in rice cv. IR64 and Hawara Bunar, and to construct a phylogenetic tree of genes that regulate rice plant height and tiller number. Gene expression analysis was conducted using the qRT-PCR technique, while the phylogenetic tree was constructed based on the Neighbor-Joining method using PAUP4 software. The results showed TAD1 gene expression in the tillering phase of rice cv. Hawara Bunar is higher than the cv. IR64. The gene expression level in both cultivars corresponds to the plant height and tiller number characters in both rice cultivars. Phylogenetic analysis showed that the TAD1 gene clustered with genes that cause the rice to have a tall habitus with few tillers. The results of a transcriptome meta-analysis reinforced the phylogenetic tree, which shows that the TAD1 gene was found in a group of downregulated genes based on the volcano plots. Therefore, the TAD1 gene can be selected as a target gene for editing in rice cv. Hawara Bunar to obtain superior characters.

Fine-mapping of a major QTL controlling plant height by BSA-seq and transcriptome sequencing in cotton.

GhSOT (GH_D05G3950) plays a negative role in regulating plant height development by modulating the GA signaling. Plant height is an important indicator affecting mechanical harvesting for cotton. Therefore, understanding the genes associated with the plant height is crucial for cotton breeding and production. In this study, we used bulk segregant analysis sequencing to identify a new quantitative trait locu (QTL) called qPH5.1, which is linked to plant height. Local QTL mapping using seven kompetitive allele-specific PCR(KASP) markers and linkage analysis successfully narrowed down qPH5.1 to ~ 0.34 Mb region harbored five candidate genes. Subsequently, RNA sequencing (RNA-seq) analysis and examination of expression patterns revealed that GhSOT exhibited the highest likelihood of being the candidate gene responsible for the plant height at this locus. Seven SNP site variations were identified in the GhSOT promoter between the two parents, and Luciferase experiments confirmed that the promoter of GhSOT from cz3 enhances downstream gene expression more effectively. Additionally, suppression of GhSOT in cz3 resulted in the restoration of plant height, further emphasizing the functional significance of this gene. Application of exogenous gibberellin acid (GA) significantly restored plant height in cz3, as demonstrated by RNA-seq analysis and exogenous hormone treatment, which revealed alterations in genes associated with GA signaling pathways. These results reveal GhSOT is a key gene controlling plant height, which may affect plant height by regulating GA signaling.

PmLBD3 links auxin and brassinosteroid signalling pathways on dwarfism in Prunus mume

BackgroundGrafting with dwarf rootstock is an efficient method to control plant height in fruit production. However, the molecular mechanism remains unclear. Our previous study showed that plants with Prunus mume (mume) rootstock exhibited a considerable reduction in plant height, internode length, and number of nodes compared with Prunus persica (peach) rootstock. The present study aimed to investigate the mechanism behind the regulation of plant height by mume rootstocks through transcriptomic and metabolomic analyses with two grafting combinations, ‘Longyan/Mume’ and ‘Longyan/Peach’.ResultsThere was a significant decrease in brassinolide levels in plants that were grafted onto mume rootstocks. Plant hormone signal transduction and brassinolide production metabolism gene expression also changed significantly. Flavonoid levels, amino acid and fatty acid metabolites, and energy metabolism in dwarf plants decreased. There was a notable upregulation of PmLBD3 gene expression in plant specimens that were subjected to grafting onto mume rootstocks. Auxin signalling cues promoted PmARF3 transcription, which directly controlled this upregulation. Through its binding to PmBAS1 and PmSAUR36a gene promoters, PmLBD3 promoted endogenous brassinolide inactivation and inhibited cell proliferation.ConclusionsAuxin signalling and brassinolide levels are linked by PmLBD3. Our findings showed that PmLBD3 is a key transcription factor that regulates the balance of hormones through the auxin and brassinolide signalling pathways and causes dwarf plants in stone fruits.

Strigolactone-gibberellin crosstalk mediated by a distant silencer fine-tunes plant height in upland cotton

Optimal plant height is crucial in modern agriculture, influencing lodging resistance and facilitating mechanized crop production. Upland cotton (Gossypium hirsutum) is the most important fiber crop globally; however, the genetic basis underlying plant height remains largely unexplored. In this study, we conducted a genome-wide association study to identify a major locus controlling plant height (PH1) in upland cotton. This locus encodes gibberellin 2-oxidase 1A (GhPH1) and features a 1133-bp structural variation (PAVPH1) located approximately 16 kb upstream. The presence or absence of PAVPH1 influences the expression of GhPH1, thereby affecting plant height. Further analysis revealed that a gibberellin-regulating transcription factor (GhGARF) recognizes and binds to a specific CATTTG motif in both the GhPH1 promoter and PAVPH1. This interaction downregulates GhPH1, indicating that PAVPH1 functions as a distant upstream silencer. Intriguingly, we found that DWARF53 (D53), a key repressor of the strigolactone (SL) signaling pathway, directly interacts with GhGARF to inhibit its binding to targets. Moreover, we identified a previously unrecognized gibberellin-SL crosstalk mechanism mediated by the GhD53-GhGARF-GhPH1/PAVPH1 module, which is crucial for regulating plant height in upland cotton. These findings shed light on the genetic basis and gene interaction network underlying plant height, providing valuable insights for the development of semi-dwarf cotton varieties through precise modulation of GhPH1 expression.

HvWOX3A Gene Controls Plant Height and Leaf Size in Barley

HvWOX3A Gene Controls Plant Height and Leaf Size in Barley

Analysis of Genetic Architecture through Generation Mean Analysis for Yield and Yield Contributing Traits in Crosses of Indian Mustard (Brassica juncea)

Generation mean analysis was deployed to study the inheritance of 12 yield and its component traits in two crosses viz. PR-2009-6 × ALBELI (Family A) and PR-2009-6 × RGN-73 (Family B) of Indian mustard [Brassica juncea (L.) Czern& Coss] for parents P1 and P2, F1 , F2 , BC1 and BC2 generations. Analysis of variance showed presence of significant variability among families and also within families (among progenies) for various traits under study except for days to maturity, seeds per siliquae and siliquae length. Family A showed considerable interaction effects for siliquae on main raceme, number of seeds per siliquae and oil content. Family B displayed epistatic interactions for characters such as plant height, length of main raceme, siliquae on main raceme, siliquae length, oil content seed yield per plant and glucosinolate content. Fixable effects [d] and [i] were found important in the inheritance of plant height, seed yield per plant and glucosinolate content. Among non fixable effects, dominance [h] gene action was significantly important for determining length of main raceme, number of siliquae on main raceme, siliquae length, oil content, seed yield per plant and glucosinolate content. Interaction gene effects were found significant in controlling plant height, length of main raceme, number of secondary branches per plant, siliquae on main raceme, siliqua length,1000-seed weight, oil content, seed yield per plant and glucosinolate content. Thus, both main effects and epistatic effects were found important in controlling the various traits under study.

Genetic Analysis of an F2 Population Derived from the Cotton Landrace Hopi Identified Novel Loci for Boll Glanding.

Landraces are an important reservoir of genetic variation that can expand the narrow genetic base of cultivated cotton. In this study, quantitative trait loci (QTL) analysis was conducted using an F2 population developed from crosses between the landrace Hopi and inbred TM-1. A high-density genetic map spanning 2253.11 and 1932.21 cM for the A and D sub-genomes, respectively, with an average marker interval of 1.14 cM, was generated using the CottonSNP63K array. The linkage map showed a strong co-linearity with the physical map of cotton. A total of 21 QTLs were identified, controlling plant height (1), bract type (1), boll number (1), stem color (2), boll pitting (2), fuzz fiber development (2), boll shape (3), boll point (4), and boll glanding (5). In silico analysis of the novel QTLs for boll glanding identified a total of 13 candidate genes. Analysis of tissue-specific expression of the candidate genes suggests roles for the transcription factors bHLH1, MYB2, and ZF1 in gland formation. Comparative sequencing of open reading frames identified early stop codons in all three transcription factors in Hopi. Functional validation of these genes offers avenues to reduce glanding and, consequently, lower gossypol levels in cottonseeds without compromising the defense mechanisms of the plant against biotic stresses.

Research on the Effects of the Relationship between Agronomic Traits and Dwarfing Genes on Yield in Colored Wheat.

This research focuses on 72 approved varieties of colored wheat from different provinces in China. Utilizing coefficients of variation, structural equation models, and correlation analyses, six agronomic traits of colored wheat were comprehensively evaluated, followed by further research on different dwarfing genes in colored wheat. Using the entropy method revealed that among the 72 colored wheat varieties, 10 were suitable for cultivation. Variety 70 was the top-performing variety, with a comprehensive index of 87.15%. In the final established structural equation model, each agronomic trait exhibited a positive direct effect on yield. Notably, plant height, spike length, and flag leaf width had significant impacts on yield, with path coefficients of 0.55, 0.40, and 0.27. Transcriptome analysis and real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) validation were used to identify three dwarfing genes controlling plant height: Rht1, Rht-D1, and Rht8. Subsequent RT-qPCR validation clustering heatmap results indicated that Rht-D1 gene expression increased with the growth of per-acre yield. Rht8 belongs to the semi-dwarf gene category and has a significant positive effect on grain yield. However, the impact of Rht1, as a dwarfing gene, on agronomic traits varies. These research findings provide crucial references for the breeding of new varieties.

Fertiliser supplementation with a PGR complex of chlormequat chloride (CCC) and paclobutrazol (PBZ) alters Cannabis sativa growth

ABSTRACT Cannabis (Cannabis sativa) is a high-value crop, wherein growth within controlled environments is common for the purposes of maximising yield, quality, and uniformity, however, uncontrolled-growth in proximity to artificial lighting can compromise yields. Within the floricultural industry it is common practice to apply plant growth regulators (PGRs) to retard plant growth and maximise yield and quality, with two well-established PGRs being chlormequat chloride (CCC) and paclobutrazol (PBZ). Accordingly, the aim of this study was to investigate the potential of a PGR complex of CCC and PBZ for novel application to cannabis to control plant height. Treatment of cannabis with the PGR complex within an indoor hydroponic growth system resulted in a 91.1% reduction in post-treatment plant growth (p < 0.001) leading to plants with end-point height and internodal spacing (INS) 0.568-fold (p < 0.001) and 0.469-fold (p < 0.001) shorter than control plants, respectively. These results demonstrate the capacity of CCC and PBZ to beneficially halt the growth of cannabis. Accordingly, application of these PGRs in combination may be utilised to restrict cannabis height without compromising yield within commercial cultivation.

Polyploidized rice improves plant height and yield through regulation of the expression of yield-related genes

Polyploidization is one of the most effective ways to improve plant height and yield in rice (&lt;i&gt;Oryza sativa&lt;/i&gt; L.). However, the molecular mechanism of its regulation is not yet fully understood. Here, we investigated the agronomic traits of diploid (‘Balilla- 2x’) and tetraploid (‘Balilla-4x’) lines of the japonica rice variety ‘Balilla’. Compared with ‘Balilla-2x’, ‘Balilla-4x’ exhibited significantly increased plant height, spike length and yield per plant. RNA-seq analysis showed that the expression levels of yield-related genes controlling plant height and panicle development (e.g., &lt;i&gt;STH1&lt;/i&gt;,&lt;i&gt;OsYUC9&lt;/i&gt; and &lt;i&gt;OsDEP1&lt;/i&gt;) were significantly upregulated in ‘Balilla-4x’ rice plants. These results indicated that polyploidization changed the expression of genes related to agronomic traits such as plant height and spike length, thereby increasing rice yield. is study provides a further basis for understanding the yield of rice after polyploidization and can serve as a new theoretical reference for breeding high-yielding rice varieties.

The Function of SD1 on Shoot Length and its Pyramiding Effect on Shoot Length and Plant Height in Rice (Oryza sativa L.)

Strong seedling vigor is imperative to achieve stable seedling establishment and enhance the competitiveness against weeds in rice direct seeding. Shoot length (SL) is one of the important traits associated with seedling vigor in rice, but few genes for SL have been cloned so far. In the previous study, we identified two tightly linked and stably expressed QTLs for SL, qSL-1f and qSL-1d by genome-wide association study, and cloned the causal gene (LOC_Os01g68500) underlying qSL-1f. In the present study, we identify LOC_Os01g66100 (i.e. the semidwarf gene SD1), a well-known gene controlling plant height (PH) at the adult-plant stage, as the causal gene underlying qSL-1d through gene-based haplotype analysis and knockout transgenic verification. By measuring the phenotypes (SL and PH) of various haplotypes of the two genes and their knockout lines, we found SD1 and LOC_ Os01g68500 controlled both SL and PH, and worked in the same direction, which provided the directly genetic evidence for a positive correlation between SL and PH combined with the analysis of SL and PH in the diverse natural population. Moreover, the knockout transgenic experiments suggested that SD1 had a greater effect on PH compared with LOC_ Os01g68500, but no significant difference in the effect on SL. Further investigation of the pyramiding effects of SD1 and LOC_Os01g68500 based on their haplotype combinations suggested that SD1 may play a dominant role in controlling SL and PH when the two genes coexist. In this study, the effect of SD1 on SL at the seedling stage is validated. In total, two causal genes, SD1 and LOC_ Os01g68500, for SL are cloned in our studies, which controlled both SL and PH, and the suitable haplotypes of SD1 and LOC_ Os01g68500 are beneficial to achieve the desired SL and PH in different rice breeding objectives. These results provide a new clue to develop rice varieties for direct seeding and provide new genetic resources for molecular breeding of rice with suitable PH and strong seedling vigor.

Transcription factor PbNAC71 regulates xylem and vessel development to control plant height.

Dwarfism is an important agronomic trait in fruit breeding programs. However, the germplasm resources required to generate dwarf pear (Pyrus spp.) varieties are limited. Moreover, the mechanisms underlying dwarfism remain unclear. In this study, "Yunnan" quince (Cydonia oblonga Mill.) had a dwarfing effect on "Zaosu" pear. Additionally, the dwarfism-related NAC transcription factor gene PbNAC71 was isolated from pear trees comprising "Zaosu" (scion) grafted onto "Yunnan" quince (rootstock). Transgenic Nicotiana benthamiana and pear OHF-333 (Pyrus communis) plants overexpressing PbNAC71 exhibited dwarfism, with a substantially smaller xylem and vessel area relative to the wild-type controls. Yeast one-hybrid, dual-luciferase, chromatin immunoprecipitation-qPCR, and electrophoretic mobility shift assays indicated that PbNAC71 downregulates PbWalls are thin 1 expression by binding to NAC-binding elements in its promoter. Yeast two-hybrid assays showed that PbNAC71 interacts with the E3 ubiquitin ligase PbRING finger protein 217 (PbRNF217). Furthermore, PbRNF217 promotes the ubiquitin-mediated degradation of PbNAC71 by the 26S proteasome, thereby regulating plant height as well as xylem and vessel development. Our findings reveal a mechanism underlying pear dwarfism and expand our understanding of the molecular basis of dwarfism in woody plants.

Effect of Mepiquat Chloride and Nitrogen levels on yield and economics of Bt (Bacillus thuringiensis) cotton

A field experiment was conducted in Bt cotton during the kharif season 2018 at the National Seed Production Area of Choudhary Charan Singh Haryana Agricultural University, Hisar. As cotton has indeterminate growth habit, so to control plant height and encourages the translocation of photosynthesis towards reproductive sinks (growing cotton bolls), which lead to higher yields this experiment was conducted in factorial R.B.D with three replications comprising three levels of Nitrogen (N1: 100% RDF, N2: 125%RDF, N3: 150%RDF) and three different doses of growth retardant (G1: Control, G2: Mepiquat chloride application 20g a.i./ha. at 60 DAS, G3: Mepiquat chloride application 20g a.i./ha at 60 DAS and 75 DAS). The results indicated that several bolls/m2, boll weight (g), and seed cotton yield (kg/ha) was higher at 150% and 125% RDF than 100% RDF. However, seed index is significantly high with 100% RDF. A number of bolls/m2, boll weight (g) and seed cotton yield (kg/ha) was significantly higher with twice the spray of mepiquat chloride at 60 and 75 DAS compared to the control. Similarly highest gross and net return was recorded with 150% RDF level of nitrogen followed by 125% RDF and 100% RDF. Among spraying of mepiquat chloride higher gross returns and net returns was recorded with two sprays of mepiquat chloride (Rs.1,87,138/ha&amp; 95,850/ha) followed by single spray (Rs 1,82,457/ha &amp; Rs 92,473/ha) and control (Rs 1,66,902/ha &amp;Rs 88,364/ha).

Assessing the impact of plant growth regulators on anther retention and Fusarium head blight in spring wheat (Triticum aestivum L.) infected by Fusarium graminearum in field conditions

Fusarium head blight (FHB) resistance in wheat is often associated with undesirable agronomic traits such as tall plant height and a propensity for lodging. Plant height in wheat is genetically controlled by some semi-dwarfing alleles that alter the plant's sensitivity to gibberellins (GAs). The presence of semi-dwarfing alleles increases the frequency of anther retention, which may contribute to FHB susceptibility by providing an initiation site for infection. The application of plant growth regulators (PGRs) may enable farmers to grow the most resistant cultivars while controlling plant height to minimize lodging risk. In this study, five spring wheat cultivars that differed in level of FHB resistance, height, and semi-dwarfing alleles were tested to determine the effect of PGRs, specifically Manipulator™ and Ethrel™, on plant height, anther retention, and FHB resistance level and the interactions between them in Winnipeg and Carman, Manitoba in 2019 and 2020. Combined field results showed that Ethrel™ significantly reduced plant height. Both PGRs did not affect the anther retention or FHB resistance levels of the tested cultivars under dry conditions. There were significant interactions between variables, but they were relatively small compared to the main treatment and cultivars. Based on the results of this study, producers could benefit from the higher levels of FHB resistance often associated with tall cultivars and use PGRs to manage plant height and lodging without increased risk of FHB.

A significant P value: How phosphorus controls plant height.

A significant P value: How phosphorus controls plant height.

Dosage response to reduced height‐1 (Rht‐1) loss‐of‐function mutations and characterization of slender phenotype in hexaploid wheat

AbstractThe reduced height (Rht‐1) genes in wheat (Triticum aestivum L.) are integral in controlling plant height. Previous studies in other plant species have demonstrated that loss‐of‐function mutations in their orthologous Rht‐1 genes results in plants with a slender phenotype illustrated by increased plant heights, sterility, and a constitutive gibberellic acid (GA3) response; however, this phenotype has not been described in wheat. In this study, nonsense alleles occurring in the GRAS domain of Rht‐A1, B1, and D1 were combined to create single, double, and triple Rht‐1 mutants. Homozygous lines possessing none, one, two, or three Rht‐1 stop mutations were grown in replicated field trials in three environments to assess agronomic traits. Germination tests to measure GA3 responsiveness and gene expression analysis via RNA‐seq were also performed. Rht‐1 triple mutants exhibited a slender phenotype characterized by rapid growth, elongated coleoptiles and internodes, elongated spikes, decreased tiller and spikelet number, and sterile heads. The presence of a single functional Rht‐1 gene resulted in a normal phenotype. Differences in plant height among the Rht‐1 double mutants, Rht‐1 single mutants, and Rht‐1 all wild‐type dosages trended toward increased plant height with increased Rht‐1 stop mutation dosage. Differences in Rht‐1 homeolog gene expression did not equate to differences in plant height between the different Rht‐1 stop mutations.