Plant Organ Size Research Articles

Deer grazing drove an assemblage‐level evolution of plant dwarfism in an insular system

Abstract Plant dwarfism, a syndrome characterised by a significant reduction in plant height and organ size, is a widely observed pattern of stress‐tolerant life‐form evolution that results from local adaptation to harsh environmental conditions. The drivers of assemblage‐level dwarfism have primarily been attributed to abiotic factors, such as low temperature, aridity, poor soil fertility or frequent fires. While biotic factors such as grazing pressure from herbivores can contribute to the establishment of plant dwarfism, these factors have rarely been tested at assemblage levels. Focusing on a dwarf plant assemblage comprising over 80 taxa on a small continental island in Japan with a high deer density, we hypothesised that historical deer grazing could also be a factor contributing to the large‐scale convergent evolution of dwarfism. To test this hypothesis, we measured the size of 1908 individual plants of 40 taxa pairs, comprising both palatable and unpalatable pairs from the island and their counterpart taxa from neighbouring regions, and sought to assess which factors (i.e. low solar radiation, estimated divergence time, low nutrient conditions and grazing pressure from deer) may have contributed to the formation of the dwarf plant assemblage on the island. We also performed genetic analysis to infer the time frames for the establishment of dwarf taxa. Statistical analyses revealed that plant size was significantly reduced mainly among the palatable taxa growing on the island, with preferential grazing by deer being identified as the most significant factor influencing plant size. Furthermore, genetic analyses revealed that dwarf ecotypes may have evolved over tens of thousands of years. Synthesis: To the best of our knowledge, this study is the first to demonstrate that interactions with herbivores can shape the assemblage‐level convergence of plant dwarfism. These findings enhance our current understanding of the formation of plant functional diversity.

Rotated Lorenz Curves of Biological Size Distributions Follow Two Performance Equations

The Lorenz curve is used to describe the relationship between the cumulative proportion of household income and the number of households of an economy. The extent to which the Lorenz curve deviates from the line of equality (i.e., y = x) is quantified by the Gini coefficient. Prior models are based on the simulated and empirical data of income distributions. In biology, the Lorenz curves of cell or organ size distributions tend to have similar shapes. When the Lorenz curve is rotated by 135 degrees counterclockwise and shifted to the right by a distance of 2, a three-parameter performance equation (PE), and its generalized version with five parameters (GPE), accurately describe this rotated and right-shifted curve. However, in prior studies, PE and GPE were not compared with the other Lorenz equations, and little is known about whether the skewness of the distribution could influence the validity of these equations. To address these two issues, simulation data from the beta distributions with different skewness values and six empirical datasets of plant (organ) size distributions were used to compare PE and GPE with three other Lorenz equations in describing the rotated and right-shifted plant (organ) size distributions. The root-mean-square error and Akaike information criterion were used to assess the validity of the two performance equations and the three other Lorenz equations. PE and GPE were both validated in describing the rotated and right-shifted simulation and empirical data of plant (organ) distributions. Nevertheless, GPE worked better than PE and the three other Lorenz equations from the perspectives of the goodness of fit, and the trade-off between the goodness of fit and the model structural complexity. Analyses indicate that GPE provides a powerful tool for quantifying size distributions across a broad spectrum of organic entities and can be used in a variety of ecological and evolutionary applications. Even for the simulation data from hypothetical extreme skewed distribution curves, GPE still worked well.

A dynamic ubiquitination balance of cell proliferation and endoreduplication regulators determines plant organ size.

Ubiquitination plays a crucial role throughout plant growth and development. The E3 ligase DA2 has been reported to activate the peptidase DA1 by ubiquitination, hereby limiting cell proliferation. However, the molecular mechanisms that regulate DA2 remain elusive. Here, we demonstrate that DA2 has a very high turnover and auto-ubiquitinates with K48-linkage polyubiquitin chains, which is counteracted by two deubiquitinating enzymes, UBIQUITIN-SPECIFIC PROTEASE 12 (UBP12) and UBP13. Unexpectedly, we found that auto-ubiquitination of DA2 does not influence its stability but determines its E3 ligase activity. We also demonstrate that impairing the protease activity of DA1 abolishes the growth-reducing effect of DA2. Last, we show that synthetic, constitutively activated DA1-ubiquitin fusion proteins overrule this complex balance of ubiquitination and deubiquitination and strongly restrict growth and promote endoreduplication. Our findings highlight a nonproteolytic function of K48-linked polyubiquitination and reveal a mechanism by which DA2 auto-ubiquitination levels, in concert with UBP12 and UBP13, precisely monitor the activity of DA1 and fine-tune plant organ size.

Genome-Wide Identification and Expression Analysis of the DA1 Gene Family in Sweet Potato and Its Two Diploid Relatives.

The DA1-like gene family plays a crucial role in regulating seed and organ size in plants. The DA1 gene family has been identified in several species but has not yet been reported in sweet potatoes. In this study, nine, eleven, and seven DA1s were identified in cultivated sweet potato (Ipomoea batatas, 2n = 6x = 90) and its two diploid wild relatives, I. trifida (2n = 2x = 30) and I. triloba (2n = 2x = 30), respectively. The DA1 genes were classified into three subgroups based on their phylogenetic relationships with Arabidopsis thaliana and Oryza sativa (rice). Their protein physiological properties, chromosomal localization, phylogenetic relationships, gene structure, promoter cis-elements, and expression patterns were systematically analyzed. The qRT-PCR results showed that the expression levels of four genes, IbDA1-1, IbDA1-3, IbDA1-6, and IbDA1-7, were higher in the sweet potato leaves than in the roots, fiber roots, and stems. In our study, we provide a comprehensive comparison and further the knowledge of DA1-like genes in sweet potatoes, and provide a theoretical basis for functional studies.

Comparison of four performance models in quantifying the inequality of leaf and fruit size distribution.

The inequality in leaf and fruit size distribution per plant can be quantified using the Gini index, which is linked to the Lorenz curve depicting the cumulative proportion of leaf (or fruit) size against the cumulative proportion of the number of leaves (or fruits). Prior researches have predominantly employed empirical models-specifically the original performance equation (PE-1) and its generalized counterpart (GPE-1)-to fit rotated and right-shifted Lorenz curves. Notably, another potential performance equation (PE-2), capable of generating similar curves to PE-1, has been overlooked and not systematically compared with PE-1 and GPE-1. Furthermore, PE-2 has been extended into a generalized version (GPE-2). In the present study, we conducted a comparative analysis of these four performance equations, evaluating their applicability in describing Lorenz curves related to plant organ (leaf and fruit) size. Leaf area was measured on 240 culms of dwarf bamboo (Shibataea chinensis Nakai), and fruit volume was measured on 31 field muskmelon plants (Cucumis melo L. var. agrestis Naud.). Across both datasets, the root-mean-square errors of all four performance models were consistently smaller than 0.05. Paired t-tests indicated that GPE-1 exhibited the lowest root-mean-square error and Akaike information criterion value among the four performance equations. However, PE-2 gave the best close-to-linear behavior based on relative curvature measures. This study presents a valuable tool for assessing the inequality of plant organ size distribution.

Structural diversity is better associated with forest productivity than species or functional diversity.

Understanding the relationship between biodiversity and productivity can be advanced by improving metrics used to quantify biodiversity. Structural diversity, that is, variation of size and form of plant organs, is an emerging biodiversity metric. However, compared with the other biodiversity metrics, its relative importance in specific components of forest productivity, for example, recruitment of new individuals, biomass net change after accounting for mortality, is largely unknown, particularly across a large spatial scale with multiple influential gradients. To address the knowledge gap, we used USDA Forest Service Forest Inventory and Analysis (FIA) data across the southcentral USA from 2008 to 2017. We calculated forest biomass increments due to recruitment and growth and net change in biomass. Then, we quantified the effects of a range of abiotic and biotic variables on the biomass increments and net change. Our results showed that (1) Structural diversity was negatively associated with the two biomass increments and net change in biomass. The negative effects were supported by increased occurrences of insects and diseases with greater structural diversity. (2) Compared with species and functional diversity, structural diversity showed a better association with biomass increments and net change, suggested by its larger absolute values of standardized coefficients, and the effects of structural diversity were negative in contrast to species diversity. (3) The effects of structural diversity, stand age, and elevation differed between natural and planted forests that may stem from the differences in stand development and species composition between the two forest types. Together, structural diversity may represent an important dimension of biodiversity impacts on plant productivity, which could be related to the exacerbated disturbances with greater structural diversity.

The trxG protein ULT1 regulates Arabidopsis organ size by interacting with TCP14/15 to antagonize the LIM peptidase DA1 for H3K4me3 on target genes

Plant organ size is an important agronomic trait that makes a significant contribution to plant yield. Despite its central importance, the genetic and molecular mechanisms underlying organ size control remain to be fully clarified. Here, we report that the trithorax group protein ULTRAPETALA1 (ULT1) interacts with the TEOSINTE BRANCHED1/CYCLOIDEA/PCF14/15 (TCP14/15) transcription factors by antagonizing the LIN-11, ISL-1, and MEC-3 (LIM) peptidase DA1, thereby regulating organ size in Arabidopsis. Loss of ULT1 function significantly increases rosette leaf, petal, silique, and seed size, whereas overexpression of ULT1 results in reduced organ size. ULT1 associates with TCP14 and TCP15 to co-regulate cell size by affecting cellular endoreduplication. Transcriptome analysis revealed that ULT1 and TCP14/15 regulate common target genes involved in endoreduplication and leaf development. ULT1 can be recruited by TCP14/15 to promote lysine 4 of histone H3 trimethylation at target genes, activating their expression to determine final cell size. Furthermore, we found that ULT1 influences the interaction of DA1 and TCP14/15 and antagonizes the effect of DA1 on TCP14/15 degradation. Collectively, our findings reveal a novel epigenetic mechanism underlying the regulation of organ size in Arabidopsis.

SMALL PLANT AND ORGAN 1 (SPO1) Encoding a Cellulose Synthase-like Protein D4 (OsCSLD4) Is an Important Regulator for Plant Architecture and Organ Size in Rice

Plant architecture and organ size are considered as important traits in crop breeding and germplasm improvement. Although several factors affecting plant architecture and organ size have been identified in rice, the genetic and regulatory mechanisms remain to be elucidated. Here, we identified and characterized the small plant and organ 1 (spo1) mutant in rice (Oryza sativa), which exhibits narrow and rolled leaf, reductions in plant height, root length, and grain width, and other morphological defects. Map-based cloning revealed that SPO1 is allelic with OsCSLD4, a gene encoding the cellulose synthase-like protein D4, and is highly expressed in the roots at the seedling and tillering stages. Microscopic observation revealed the spo1 mutant had reduced number and width in leaf veins, smaller size of leaf bulliform cells, reduced cell length and cell area in the culm, and decreased width of epidermal cells in the outer glume of the grain. These results indicate the role of SPO1 in modulating cell division and cell expansion, which modulates plant architecture and organ size. It is showed that the contents of endogenous hormones including auxin, abscisic acid, gibberellin, and zeatin tested in the spo1 mutant were significantly altered, compared to the wild type. Furthermore, the transcriptome analysis revealed that the differentially expressed genes (DEGs) are significantly enriched in the pathways associated with plant hormone signal transduction, cell cycle progression, and cell wall formation. These results indicated that the loss of SPO1/OsCSLD4 function disrupted cell wall cellulose synthase and hormones homeostasis and signaling, thus leading to smaller plant and organ size in spo1. Taken together, we suggest the functional role of SPO1/OsCSLD4 in the control of rice plant and organ size by modulating cell division and expansion, likely through the effects of multiple hormonal pathways on cell wall formation.

SOD-GIF-FIT module controls plant organ size and iron uptake

Plant organ growth is controlled by various internal and external cues. However, the underlying molecular mechanisms that coordinate plant organ growth and nutrient homeostasis remain largely unknown. Recently, Zheng et al. identified the key regulators SOD7 (suppressor of da1-1) and GRF-INTERACTING FACTOR1 (GIF1) that control organ size and iron uptake in arabidopsis (Arabidopsis thaliana).

The genetic basis of traits associated with the evolution of serpentine endemism in monkeyflowers.

The floras on chemically and physically challenging soils, such as gypsum, shale, and serpentine, are characterized by narrowly endemic species. The evolution of edaphic endemics may be facilitated or constrained by genetic correlations among traits contributing to adaptation and reproductive isolation across soil boundaries. The yellow monkeyflowers in the Mimulus guttatus species complex are an ideal system in which to examine these evolutionary patterns. To determine the genetic basis of adaptive and prezygotic isolating traits, we performed genetic mapping experiments with F2 hybrids derived from a cross between a serpentine endemic, M. nudatus, and its close relative M. guttatus. Few large effect and many small effect QTL contribute to interspecific divergence in life history, floral, and leaf traits, and a history of directional selection contributed to trait divergence. Loci contributing to adaptive traits and prezygotic reproductive isolation overlap, and their allelic effects are largely in the direction of species divergence. These loci contain promising candidate genes regulating flowering time and plant organ size. Together, our results suggest that genetic correlations among traits can facilitate the evolution of adaptation and speciation and may be a common feature of the genetic architecture of divergence between edaphic endemics and their widespread relatives.

Site-directed mutagenesis of soybean PEAPOD genes using the CRISPR/Cas9 system alters tissue developmental transition.

In general, plant organ size is determined using cell number and expansion. In our previous study, we generated soybean (Glycine max) mutants of the PEAPOD (PPD) genes GmPPD1 and GmPPD2 using the clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated endonuclease 9 system. Some of these mutants exhibited extremely abnormal phenotypes, such as twisted pods and limited seeds. These phenotypes were attributed to the frameshift mutation in both GmPPD loci. In this study, the physiological and molecular biological properties of mutant plants with two knocked-out GmPPD loci (ppd-KO) were characterized. The ppd-KO mutant exhibited a delayed growth phase from the time of development of the unifoliolate leaves to that of first trifoliolate leaves and a stay-green phenotype, which were not observed in the other mutants of soybean or ppd mutants of other plant species. Gene expression analysis revealed considerably decreased expression of SPIRAL1-LIKE 5 (GmSP1L5), mainly causing the twisted pod phenotype observed in the ppd-KO mutant. The relationship between PPD and SP1L5 has not been previously reported, and in this study, we showed that that loss of PPD functioning affects SP1L5 expression in soybean. In this study, we revealed that the decrease in PPD function contributed to organ enlargement and that complete knockout of PPD has a negative effect on soybean organogenesis.

The MIO1-MtKIX8 module regulates the organ size in Medicago truncatula.

Plant organ size is an important agronomic trait tightly related to crop yield. However, the molecular mechanisms underlying organ size regulation remain largely unexplored in legumes. We previously characterized a key regulator F-box protein MINI ORGAN1 (MIO1)/SMALL LEAF AND BUSHY1 (SLB1), which controls plant organ size in the model legume Medicago truncatula. In order to further dissect the molecular mechanism, MIO1 was used as the bait to screen its interacting proteins from a yeast library. Subsequently, a KIX protein, designated MtKIX8, was identified from the candidate list. The interaction between MIO1 and MtKIX8 was confirmed further by Y2H, BiFC, split-luciferase complementation and pull-down assays. Phylogenetic analyses indicated that MtKIX8 is highly homologous to Arabidopsis KIX8, which negatively regulates organ size. Moreover, loss-of-function of MtKIX8 led to enlarged leaves and seeds, while ectopic expression of MtKIX8 in Arabidopsis resulted in decreased cotyledon area and seed weight. Quantitative reverse-transcription PCR and in situ hybridization showed that MtKIX8 is expressed in most developing organs. We also found that MtKIX8 serves as a crucial molecular adaptor, facilitating interactions with BIG SEEDS1 (BS1) and MtTOPLESS (MtTPL) proteins in M. truncatula. Overall, our results suggest that the MIO1-MtKIX8 module plays a significant and conserved role in the regulation of plant organ size. This module could be a good target for molecular breeding in legume crops and forages.

A group III patatin-like phospholipase gene pPLAIIIδ regulates lignin biosynthesis and influences the rate of seed germination in Arabidopsis thaliana.

The lignification of plant secondary walls is an important process that provides plants with mechanical support. However, the presence of lignin in the secondary walls affects the readily availability of cellulose required in various industries, including the biofuel, paper, and textile industries. Thus, plants with less lignin are ideal for usage in such industries. Molecular studies have identified genes that regulate plant lignification, including group III plant-specific patatin-related phospholipase genes. Recent studies have reported decreased lignin content when pPLAIIIα, pPLAIIIγ (from Arabidopsis thaliana), and pPLAIIIβ (from Panax ginseng) were overexpressed in Arabidopsis. However, the role played by a closely related gene pPLAIIIδ in lignin biosynthesis has not yet been reported. In this study, we found that overexpression of the pPLAIIIδ significantly reduced the lignin content in secondary cell walls, whereas the silencing of the gene increased secondary walls lignification. Transcript level analysis showed that the key structural and regulatory genes involved in the lignin biosynthesis pathway decreased in overexpression, and increased in plants with silenced pPLAIIIδ. Further analysis revealed that pPLAIIIδ played an influential role in several physiological processes including seed germination, and chlorophyll accumulation. Moreover, the gene also influenced the size of plants and plant organs, including leaves, seeds, and root hairs. Generally, our study provides important insights toward the use of genetic engineering for lignin reduction in plants and provides information about the agronomical and physiological suitability of pPLAIIIδ transgenic plants for utilization in biomass processing industries.

The AtERF19 gene regulates meristem activity and flower organ size in plants.

Ethylene-responsive factors (ERFs) have diverse functions in the regulation of various plant developmental processes. Here, we demonstrate the dual role of an Arabidopsis ERF gene, AtERF19, in regulating reproductive meristem activity and flower organ size through the regulation of genes involved in CLAVATA-WUSCHEL (CLV-WUS) and auxin signaling, respectively. We found that AtERF19 stimulated the formation of flower primordia and controlled the number of flowers produced by activating WUS and was negatively regulated by CLV3. 35S::AtERF19 expression resulted in significantly more flowers, whereas 35S::AtERF19 + SRDX dominant-negative mutants produced fewer flowers. In addition, AtERF19 also functioned to control flower organ size by promoting the division/expansion of the cells through activating Small Auxin Up RNA Gene 32 (SAUR32), which positively regulated MYB21/24 in the auxin signaling pathway. 35S::AtERF19 and 35S::SAUR32 resulted in similarly larger flowers, whereas 35S::AtERF19 + SRDX and 35S::SAUR32-RNAi mutants produced smaller flowers than the wild type. The functions of AtERF19 were confirmed by the production of similarly more and larger flowers in 35S::AtERF19 transgenic tobacco (Nicotiana benthamiana) and in transgenic Arabidopsis which ectopically expressed the orchid gene (Nicotiana benthamiana) PaERF19 than in wild-type plants. The finding that AtERF19 regulates genes involved in both CLV-WUS and auxin signaling during flower development significantly expands the current knowledge of the multifunctional evolution of ERF genes in plants. The results presented in this work indicate a dual role for the transcription factor AtERF19 in controlling the number of flowers produced and flower organ size through the regulation of genes involved in CLV-WUS and auxin signaling, respectively. Our findings expand the knowledge of the roles of ERF genes in the regulation of reproductive development.

Mapping and identification of CsSF4, a gene encoding a UDP-N-acetyl glucosamine-peptide N-acetylglucosaminyltransferase required for fruit elongation in cucumber (Cucumis sativus L.).

The short fruit length phenotype in sf4 is caused by a SNP in Csa1G665390, which encodes an O-linked N-acetylglucosamine (GlcNAc) transferase in cucumber. Cucumber fruit is an excellent resource for studying fruit morphology due to its fast growth rate and naturally abundant morphological variations. The regulatory mechanisms underlying plant organ size and shape are important and fundamental biological questions. In this study, a short-fruit length mutant, sf4, was identified from an ethyl methanesulfonate (EMS) mutagenesis population derived from the North China-type cucumber inbred line WD1. Genetic analysis indicated that the short fruit length phenotype of sf4 was controlled by a recessive nuclear gene. The SF4 locus was located in a 116.7-kb genomic region between the SNP markers GCSNP75 and GCSNP82 on chromosome 1. Genomic and cDNA sequences analysis indicated that a single G to A transition at the last nucleotide of Csa1G665390 intron 21 in sf4 changed the splice site from GT-AG to GT-AA, resulting in a 42-bp deletion in exon 22. Csa1G665390 is presumed to be a candidate gene, CsSF4 that encodes an O-linked N-acetylglucosamine (GlcNAc) transferase (OGT). CsSF4 was highly expressed in the leaves and male flowers of wild-type cucumbers. Transcriptome analysis indicated that sf4 had alterations in expression of many genes involved in hormone response pathways, cell cycle regulation, DNA replication, and cell division, suggesting that cell proliferation-associated gene networks regulate fruit development in cucumber. Identification of CsSF4 will contribute to elucidating the function of OGT in cell proliferation and to understanding fruit elongation mechanisms in cucumber.

ПОСЕВНЫЕ КАЧЕСТВА СЕМЯН И РОСТОВЫЕ ПРОЦЕССЫ НА РАННИХ ЭТАПАХ ОРГАНОГЕНЕЗА ОЗИМОЙ ПШЕНИЦЫ В ЗАВИСИМОСТИ ОТ ОБРАБОТКИ ИХ БИОПРЕПАРАТАМИ

The article presents the results of laboratory studies on the effect of biopreparations Hu-mate 7+, Growth Matrix, Ecorost, Azotovite and Phosphatovite on the sowing qualities and growth parameters of terrestrial and underground plant organs of the winter wheat variety Nemchinovs-kaya 57. The work revealed the stimulating effect of the studied biological compounds on the initial growth processes of seedlings. A significant growth-stimulating effect on root system development was observed. The excess in the root length compared to the control was 0.7–21.0 mm (102–145%). The effectiveness of the biopreparations on increase of the linear size of terrestrial plant or-gans was lower. The differences in the sprout length compared to the control were 0.9–3.5 mm (91–118%). The increase in weight of 100 sprouts compared to the control was 0–1.1 g, with maxi-mum values in the variants Azotovit and Humate 7+. The maximum efficiency index was observed for the biopreparation Humate 7+.

Factor of DNA methylation 1 affects woodland strawberry plant stature and organ size via DNA methylation.

RNA-directed DNA methylation (RdDM) is an epigenetic process that directs silencing to specific genomic regions and loci. The biological functions of RdDM are not well studied in horticultural plants. Here, we isolated the ethyl methane-sulfonate-induced mutant reduced organ size (ros) producing small leaves, flowers, and fruits in woodland strawberry (Fragaria vesca) due to reduced cell numbers compared with that in the wild-type (WT). The candidate mutation causes a premature stop codon in FvH4_6g28780, which shares high similarity to Arabidopsis (Arabidopsis thaliana) Factor of DNA Methylation1 (FDM1) encoding an RdDM pathway component and was named FveFDM1. Consistently, the fvefdm1CR mutants generated by CRISPR/Cas9 also produced smaller organs. Overexpressing FveFDM1 in an Arabidopsis fdm1-1 fdm2-1 double mutant restored DNA methylation at the RdDM target loci. FveFDM1 acts in a protein complex with its homolog Involved in De Novo 2 (FveIDN2). Furthermore, whole-genome bisulfite sequencing revealed that DNA methylation, especially in the CHH context, was remarkably reduced throughout the genome in fvefdm1. Common and specific differentially expressed genes were identified in different tissues of fvefdm1 compared to in WT tissues. DNA methylation and expression levels of several gibberellic acid (GA) biosynthesis and cell cycle genes were validated. Moreover, the contents of GA and auxin were substantially reduced in the young leaves of fvefdm1 compared to in the WT. However, exogenous application of GA and auxin could not recover the organ size of fvefdm1. In addition, expression levels of FveFDM1, FveIDN2, Nuclear RNA Polymerase D1 (FveNRPD1), Domains Rearranged Methylase 2 (FveDRM2), and cell cycle genes were greatly induced by GA treatment. Overall, our work demonstrated the critical roles of FveFDM1 in plant growth and development via RdDM-mediated DNA methylation in horticultural crops.

Natural variation of GhSI7 increases seed index in cotton.

qSI07.1, a major QTL for seed index in cotton, was fine-mapped to a 17.45-kb region, and the candidate gene GhSI7 was verified in transgenic plants. Improving production to meet human needs is a vital objective in cotton breeding. The yield-related trait seed index is a complex quantitative trait, but few candidate genes for seed index have been characterized. Here, a major QTL for seed index qSI07.1 was fine-mapped to a 17.45-kb region by linkage analysis and substitutional mapping. Only GhSI7, encoding the transcriptional regulator STERILE APETALA, was contained in the candidate region. Association test and genetic analysis indicated that an 845-bp-deletion in its intron was responsible for the seed index variation. Origin analysis revealed that this variation was unique in Gossypium hirsutum and originated from race accessions. Overexpression of GhSI7 (haplotype 2) significantly increased the seed index and organ size in cotton plants. Our findings provided a diagnostic marker for breeding and selecting cotton varieties with high seed index, and laid a foundation for further studies to understand the molecular mechanism of cotton seed morphogenesis.

PIF7 is a master regulator of thermomorphogenesis in shade

The size of plant organs is highly responsive to environmental conditions. The plant’s embryonic stem, or hypocotyl, displays phenotypic plasticity, in response to light and temperature. The hypocotyl of shade avoiding species elongates to outcompete neighboring plants and secure access to sunlight. Similar elongation occurs in high temperature. However, it is poorly understood how environmental light and temperature cues interact to effect plant growth. We found that shade combined with warm temperature produces a synergistic hypocotyl growth response that dependent on PHYTOCHROME-INTERACTING FACTOR 7 (PIF7) and auxin. This unique but agriculturally relevant scenario was almost totally independent on PIF4 activity. We show that warm temperature is sufficient to promote PIF7 DNA binding but not transcriptional activation and we demonstrate that additional, unknown factor/s must be working downstream of the phyB-PIF-auxin module. Our findings will improve the predictions of how plants will respond to increased ambient temperatures when grown at high density.

Implementasi Pemupukan NPK pada Budidaya Labu Madu Hibrida

One type of pumpkin that is still rarely cultivated by the Indonesian people is the honey gourd, while the honey gourd is rich in benefits that are good for health and the honey gourd has high economic value because it is still rarely cultivated. In addition, the relatively higher price of honey compared to other yellows makes this pumpkin a sufficient source of income for farmers. One of the efforts to meet the demand for honey pumpkin yields is to use the right dose of NPK fertilizer on honey pumpkin plants. The study used a randomized block design (RAK) with 6 doses of fertilization treatment, repeated 4 times. So the total experiment is 24 plants. The treatments used were R0 without chemical fertilizer, R1 at 20% dose of chemical fertilizer, R2 40% dose of chemical fertilizer, R3 60% dose of chemical fertilizer, R4 80% dose of chemical fertilizer and R5 100% dose of chemical fertilizer. The results showed that the fertilizer dose of 20% (R1) gave the best effect on the finished fruit to harvest and fruit weight. The dose of fertilization has no effect on the growth and size of plant organs.