Ideal Plant Research Articles

The inhibitory potential of chemical constituents of Ficus carica targeting interleukin-6 (IL-6) mediated inflammation.

Inflammation is an innate reaction of the body of an individual when subjected to the noxious factors repeatedly. Pharmacological approaches focused at disrupting cytokine signaling networks have become significant therapeutic alternatives for the treatment of inflammatory illnesses, cancer and autoimmune disorders. High levels of inflammatory mediators, particularly interleukin IL-1, IL-6, IL-18, IL-12, and tumor necrosis factor alpha leads to a cytokine storm in the body. Among all the released cytokines in a patient suffering from inflammatory disorder, IL-6 mediator has a pivotal role in this inflammatory cascade which progresses to a cytokine storm. Therefore, the blockage of the IL-6 inflammatory mediator could be a promising treatment option for the patients with hyper inflammatory conditions. The phytochemicals could provide the new lead compounds against the IL-6 mediator. Ficus carica has been the ideal plant of research and investigation due to its commercial, economic and medical importance. The anti-inflammatory properties of F. carica were further investigated by in silico and in vivo approaches. The docking scores of Cyanidin-3,5-diglucoside, Kaempferol-7-O-rutinoside, Cyanidin-3-rhamnoglucoside, and Rutin are -9.231, -8.921, -8.840, and -8.335 Kcal/mole respectively. The free energy of binding and stability of the docked complexes of these top four phytochemicals with the IL-6 were further analyzed by Molecular Mechanics-Generalized Born Surface Area and Molecular Dynamic simulations, respectively. The in vivo anti-inflammatory carrageenan-induced rat paw edema model was used for the validation of in silico results. The maximum percentage paw edema inhibition with petroleum ether and ethyl acetate was 70.32% and 45.05%, respectively. The in vivo anti-inflammatory activity confirms the anti-inflammatory potential of F. carica. Therefore, it is predicted that Cyanidin-3,5-diglucoside, Kaempferol-7-O-rutinoside, Cyanidin-3-rhamnoglucoside, and Rutin have the potential to inhibit the IL-6 mediator which will aid in mitigating the cytokine storm in patients with acute inflammations.

UAV-based time-series phenotyping reveals the genetic basis of plant height in upland cotton.

Plant height (PH) is an important agronomic trait affecting crop architecture, biomass, resistance to lodging and mechanical harvesting. Elucidating the genetic governance of plant height is crucial because of the global demand for high crop yields. However, during the rapid growth period of plants the PH changes a lot on a daily basis, which makes it difficult to accurately phenotype the trait by hand on a large scale. In this study, an unmanned aerial vehicle (UAV)-based remote-sensing phenotyping platform was applied to obtain time-series PHs of 320 upland cotton accessions in three different field trials. The results showed that the PHs obtained from UAV images were significantly correlated with ground-based manual measurements, for three trials (R2 = 0.96, 0.95 and 0.96). Two genetic loci on chromosomes A01 and A11 associated with PH were identified by genome-wide association studies (GWAS). GhUBP15 and GhCUL1 were identified to influence PH in further analysis. We obtained a time series of PH values for three field conditions based on remote sensing with UAV. The key genes identified in this study are of great value for the breeding of ideal plant architecture in cotton.

Metabolomic Analysis of the Response of Haloxylon ammodendron and Haloxylon persicum to Drought.

Haloxylon ammodendron and Haloxylon persicum, as typical desert plants in arid areas, show strong drought tolerance and environmental adaptability and are therefore ideal model plants for studying the molecular mechanisms of drought tolerance. A metabolomic analysis of H. ammodendron and H. persicum in their natural environment is lacking, and their metabolic response to drought therefore remains unclear. To elucidate the response of H. ammodendron and H. persicum to drought at the metabolic level, a non-targeted metabolomics analysis was carried out herein. Under a dry environment, H. ammodendron exhibited 296 and 252 differentially expressed metabolites (DEMs) in the positive and negative ion modes, respectively, whereas 452 and 354 DEMs were identified in the positive and negative ion modes in H. persicum, respectively. The results indicated that H. ammodendron responds to drought by increasing the content of organic nitrogen compounds and lignans, neolignans, and related compounds, and reducing the content of alkaloids and derivatives. By contrast, H. persicum adapts to the dry environment by increasing the content of organic acids and their derivatives and reducing the content of lignans, neolignans, and related compounds. In addition, H. ammodendron and H. persicum improved their osmoregulation ability, reactive oxygen species detoxification ability, and cell membrane stability by regulating the key metabolic pathways and anabolism of associated metabolites. This is the first metabolomics report on the response of H. ammodendron and H. persicum to drought in their natural environment, providing a foundation for the further study of their regulatory mechanisms under drought stress.

Growth characteristics and post trimming regrowth potential of tropical and sub-tropical landscape hedge plants in response to spacing

Spacing of landscape plants is one of the factors determining the outcome of a design in terms of canopy formation which is one of the variables for aesthetic appearance in terms of shapes and forms. This study was conducted between September 2016 and September 2017, to determine the appropriate intra-row spacing for five plant species in hedge formation. The plant species used were Duranta erecta, Hamelia patens, Ficus retusa, Buxus sempervirens and Acalypha wilkesiana. Transplanting was done at intra-row spacing of 30, 40, 50 and 60cm and a constant inter-row spacing of 100cm. The experiment was a Randomized Complete Block Design in split plot arrangement with three replicates. Plant height, number of leaves, number of branches and canopy space, as indices of species suitability for use as hedge, were measured fortnightly. Plant regrowth and aesthetic characteristics were assessed after periodic trimming. H. patens and B. sempervirens species had the tallest plants. B. sempervirens and D. erecta produced the highest number of leaves while D. erecta and H. patens had the highest number of branches. D. erecta had significantly (p<0.05) the fastest post-trimming shoot regrowth rate relative to other species following the 1st and 2nd trimming (25 and 28 WAT respectively). The effect of spacing on shoot regrowth length was significant after the 3rd, 4th and 5th trimmings (31, 34 and 37 WAT respectively). The highest shoot regrowth height was recorded at 40cm spacing followed by 30cm intra row spacing. All species responded best at 50cm intra-row spacing for the number of branches and canopy space as well as early hedge formation. The study concluded that B. sempervirens was suitable for ideal hedging at 40cm intra-row spacing while A. wilkiesiana and H. patens were only suitable as informal hedges. Hence, B. sempervirens species is recommended as the ideal hedge plant choice based on its early regrowth after trimming, high leaf and branch production as well as overall speed in hedge formation at 31WAT.

Where to build the ideal solar-powered ammonia plant? Design optimization of a Belgian and Moroccan power-to-ammonia plant for covering the Belgian demand under uncertainties

Regions with abundantly available renewable energy are not necessarily the same as those with a high population density and energy consumption. Therefore, renewable energy can be produced in optimal climate conditions with a remote renewable hub and transported to these population-dense regions. To establish this energy transport to these regions, ammonia provides a flexible, easy-to-handle energy carrier. However, current literature rarely considers the impact of techno-economic uncertainty on the feasibility of this transport. Using those uncertainties, we performed a robust design optimization on the levelized cost of ammonia and the power-to-ammonia efficiency to compare the local (Belgium) and remote (Morocco) ammonia production and transport to Belgium. This paper provides the robust designs (i.e. least sensitive to uncertainty) for local and remote renewable ammonia production and the advantages of both approaches on the levelized cost and energy efficiency. The results confirm that ammonia production in regions with high solar irradiance followed by the transport of ammonia is cost-effective and robust (601 euro/tonneNH3 in mean and 98 euro/tonneNH3 in standard deviation) over local production (852 euro/tonneNH3 in mean and 139 euro/tonneNH3 in standard deviation). However, local ammonia production provides for more efficient (54.8% in mean) and less sensitive power-to-ammonia plant designs (0.16% in standard deviation), while the production in Morocco is less efficient (52.2% in mean) and more sensitive to uncertainties (0.39% in standard deviation). The capacity of the photovoltaic arrays and the electrolyzers highly influences both objectives. The sensitivity analysis shows that capital and operational expenses of the photovoltaics and electrolyzer stack dominate the designs with the lowest levelized cost in mean and standard deviation. However, the energy consumption uncertainty of the Haber–Bosch also impacts the cost of the lowest mean levelized cost. This uncertainty also dominates the designs with the highest energy efficiency in mean and lowest standard deviation.

Comparative Assessment of the Functional Efficiency of Arboriflora Species Composition in Urban Green Spaces

The article discusses the results of a comprehensive analysis of the ecological state and environment-stabilizing functions of the species composition of arboriflora in the urban planting structure. It’s based on a large amount of factual material obtained during the course of a long-term monitoring of Vladivostok’s urban greenery. A methodological substantiation has been developed for a comprehensive qualitative-quantitative assessment of species using the applied qualimetry techniques. An integral indicator, named the coefficient of the functional efficiency of the species (JFEC) was proposed as the main evaluation unit. It is a relative-quantitative magnitude of plants quality that characterises their functional efficiency and significance in urban ecosystems: prevalence in greenery planting, vitality, the ability for accumulation of the priority pollutant metals in the urban environment, their concentration relative to the local ecological background; the capability for accumulating metals from the soil. Comparative analysis of the functional efficiency of 80 species of trees and shrubs forming the urban greenery of Vladivostok on the basis of the proposed coefficient was carried out. Among the compared sample of plants, the JFEC decreases from 3.70 (Crataegus pinnatifida) to 1.13 (Malus mandshurica). This values measure up to 74 and 23% of the quality standard (QS), which corresponds to the ideal plant species. The groups of species of different functional significance in the urban green spaces structure have been identified. The best efficiency in creating the comfortable environmental conditions in the city was demonstrated by species widespread in landscaping: Fraxinus mandshurica, Ulmus japonica, Betula platyphylla, Physocarpus opulifolia et al. They are characterized by the maximum participation in the formation of the urban greenery structure and a high ability to absorb the main pollutants of the urban environment. The JFEC of these species is within 3.26–2.61, which corresponds to 65–52% of the QS. In conclusion, author makes a suggestion on a rational use of species for the formation of a comfortable urban environment and introduction of the results into the practice of managing the urban green fund.

Functional identification of PhMATE1 in flower color formation in petunia.

Multidrug and toxic compound extrusion (MATE) transporter proteins are a class of secondary transporter proteins that can transport flavonoids. Anthocyanins, a kind of flavonoid, are important secondary metabolites widely found in higher plants; they determine the flower color of most angiosperms. TT12 in Arabidopsis was the first MATE protein identified to be involved in flavonoid transport. Petunia (Petunia hybrida) is an important ornamental plant and is one of the ideal plants for studying plant flower color. However, there are few reports on anthocyanin transport in petunia. In this study, we characterized a homolog of Arabidopsis TT12 in the petunia genome, PhMATE1, that shares the highest amino acid sequence identity with Arabidopsis TT12. PhMATE1 protein contained 11 transmembrane helices. PhMATE1 showed a high transcription level in corollas. The silencing of PhMATE1 mediated by both virus-induced gene silence and RNA interference changed flower color and reduced anthocyanin content in petunia, suggesting that PhMATE1 is involved in anthocyanin transport in petunia. Furthermore, PhMATE1 silencing downregulated the expression of the structural genes of the anthocyanin synthesis pathway. The results of this study supported the hypothesis that MATEs are involved in the sequestration of anthocyanins during flower color formation.

Phytoremediation Prospects for Restoration of Contamination in the Natural Ecosystems

Toxic substances have a deleterious effect on biological systems if accrued in ecosystems beyond their acceptable limit. A natural ecosystem can become contaminated due to the excessive release of toxic substances by various anthropogenic and natural activities, which necessitates rehabilitation of the environmental contamination. Phytoremediation is an eco-friendly and cost-efficient method of biotechnological mitigation for the remediation of polluted ecosystems and revegetation of contaminated sites. The information provided in this review was collected by utilizing various sources of research information, such as ResearchGate, Google Scholar, the Scopus database and other relevant resources. In this review paper, we discuss (i) various organic and inorganic contaminants; (ii) sources of contamination and their adverse effects on terrestrial and aquatic life; (iii) approaches to the phytoremediation process, including phytoextraction, rhizoremediation, phytostabilization, phytovolatilization, rhizofiltration, phytodegradation, phytodesalination and phytohydraulics, and their underlying mechanisms; (iv) the functions of various microbes and plant enzymes in the biodegradation process and their potential applications; and (v) advantages and limitations of the phytoremediation technique. The reported research aimed to adequately appraise the efficacy of the phytoremediation treatment and facilitate a thorough understanding of specific contaminants and their underlying biodegradation pathways. Detailed procedures and information regarding characteristics of ideal plants, sources of heavy metal contamination, rhizodegradation techniques, suitable species and removal of these contaminants are put forward for further application. Scientists, planners and policymakers should focus on evaluating possible risk-free alternative techniques to restore polluted soil, air and water bodies by involving local inhabitants and concerned stakeholders.

Antioxidant Properties of Protein-Rich Plant Foods in Gastrointestinal Digestion-Peanuts as Our Antioxidant Friend or Foe in Allergies.

Thermally processed peanuts are ideal plant models for studying the relationship between allergenicity and antioxidant capacity of protein-rich foods, besides lipids, carbohydrates and phytochemicals. Peanut is highly praised in the human diet; however, it is rich in allergens (>75% of total proteins). One-third of peanut allergens belong to the products of genes responsible for the defence of plants against stress conditions. The proximate composition of major peanut macromolecules and polyphenols is reviewed, focusing on the identity and relative abundance of all peanut proteins derived from recent proteomic studies. The importance of thermal processing, gastrointestinal digestion (performed by INFOGEST protocol) and their influence on allergenicity and antioxidant properties of protein-rich plant food matrices is elaborated. Antioxidant properties of bioactive peptides from nuts were also considered. Moreover, there are no studies dealing simultaneously with the antioxidant and allergenic properties of protein- and polyphenol-rich foods, considering all the molecules that can significantly contribute to the antioxidant capacity during and after gastrointestinal digestion. In summary, proteins and carbohydrates are underappreciated sources of antioxidant power released during the gastrointestinal digestion of protein-rich plant foods, and it is crucial to decipher their antioxidant contribution in addition to polyphenols and vitamins before and after gastrointestinal digestion.

TaSPL14-7A is a conserved regulator controlling plant architecture and yield traits in common wheat (Triticum aestivum L.).

Plant architecture is a crucial influencing factor of wheat yield and adaptation. In this study, we cloned and characterized TaSPL14, a homologous gene of the rice ideal plant architecture gene OsSPL14 in wheat. TaSPL14 homoeologs (TaSPL14-7A, TaSPL14-7B and TaSPL14-7D) exhibited similar expression patterns, and they were all preferentially expressed in stems at the elongation stage and in young spikes. Moreover, the expression level of TaSPL14-7A was higher than that of TaSPL14-7B and TaSPL14-7D. Overexpression of TaSPL14-7A in wheat resulted in significant changes in plant architecture and yield traits, including decreased tiller number and increased kernel size and weight. Three TaSPL14-7A haplotypes were identified in Chinese wheat core collection, and haplotype-based association analysis showed that TaSPL14-7A-Hap1/2 were significantly correlated with fewer tillers, larger kernels and higher kernel weights in modern cultivars. The haplotype effect resulted from a difference in TaSPL14-7A expression levels among genotypes, with TaSPL14-7A-Hap1/2 leading to higher expression levels than TaSPL14-7A-Hap3. As favorable haplotypes, TaSPL14-7A-Hap1/2 underwent positive selection during global wheat breeding over the last century. Together, the findings of our study provide insight into the function and genetic effects of TaSPL14 and provide a useful molecular marker for wheat breeding.

The garden asparagus (Asparagus officinalis L.) mitochondrial genome revealed rich sequence variation throughout whole sequencing data

Garden asparagus (Asparagus officinalis L.) is a horticultural crop with high nutritional and medical value, considered an ideal plant for sex determination research among many dioecious plants, whose genomic information can support genetic analysis and breeding programs. In this research, the entire mitochondrial genome of A. officinalis was sequenced, annotated and assembled using a mixed Illumina and PacBio data. The garden asparagus circular mitochondrial genome measures 492,062 bp with a GC value of 45.9%. Thirty-six protein-coding genes, 17 tRNA and 6 rRNA genes were annotated, among which 8 protein-coding genes contained 16 introns. In addition, 254 SSRs with 10 complete tandem repeats and 293 non-tandem repeats were identified. It was found that the codons of edited sites located in the amino acids showed a leucine-formation trend, and RNA editing sites mainly caused the mutual transformation of amino acids with the same properties. Furthermore, 72 sequence fragments accounting for 20,240 bp, presentating 4.11% of the whole mitochondrial genome, were observed to migrate from chloroplast to mitochondrial genome of A. officinalis. The phylogenetic analysis showed that the closest genetic relationship between A. officinalis with onion (Allium cepa) inside the Liliaceae family. Our results demonstrated that high percentage of protein-coding genes had evolutionary conservative properties, with Ka/Ks values less than 1. Therefore, this study provides a high-quality garden asparagus mitochondrial genome, useful to promote better understanding of gene exchange between organelle genomes.

MORE PANICLES 3, a natural allele of OsTB1/FC1, impacts rice yield in paddy fields at elevated CO2 levels

Improving crop yield potential through an enhanced response to rising atmospheric CO2 levels is an effective strategy for sustainable crop production in the face of climate change. Large-sized panicles (containing many spikelets per panicle) have been a recent ideal plant architecture (IPA) for high-yield rice breeding. However, few breeding programs have proposed an IPA under the projected climate change. Here, we demonstrate through the cloning of the rice (Oryza sativa) quantitative trait locus for MORE PANICLES 3 (MP3) that the improvement in panicle number increases grain yield at elevated atmospheric CO2 levels. MP3 is a natural allele of OsTB1/FC1, previously reported as a negative regulator of tiller bud outgrowth. The temperate japonica allele advanced the developmental process in axillary buds, moderately promoted tillering, and increased the panicle number without negative effects on the panicle size or culm thickness in a high-yielding indica cultivar with large-sized panicles. The MP3 allele, containing three exonic polymorphisms, was observed in most accessions in the temperate japonica subgroups but was rarely observed in the indica subgroup. No selective sweep at MP3 in either the temperate japonica or indica subgroups suggested that MP3 has not been involved and utilized in artificial selection during domestication or breeding. A free-air CO2 enrichment experiment revealed a clear increase of grain yield associated with the temperate japonica allele at elevated atmospheric CO2 levels. Our findings show that the moderately increased panicle number combined with large-sized panicles using MP3 could be a novel IPA and contribute to an increase in rice production under climate change with rising atmospheric CO2 levels.

Evidence for a trade-off between growth rate and xylem cavitation resistance in Callitris rhomboidea.

The ideal plant water transport system is one that features high efficiency and resistance to drought-induced damage (xylem cavitation), however species rarely possess both. This may be explained by trade-offs between traits, yet thus far, no proposed trade-off has offered a universal explanation for the lack water transport systems that are both highly drought-resistant and highly efficient. Here we find evidence for a new trade-off, between growth rate and resistance to xylem cavitation, in the canopies of a drought-resistant tree species (Callitris rhomboidea). Wide variation in cavitation resistance (P50) was found in distal branch tips (< 2mm in diameter), converging to low variation in P50 in larger diameter stems (> 2mm). We found a significant correlation between cavitation resistance and distal branchlet internode length across branch tips in C. rhomboidea canopies. Branchlets with long internodes (8mm or longer) were significantly more vulnerable to drought-induced xylem cavitation than shorter internodes (4mm or shorter). This suggests that varying growth rates, leading to differences in internode length, drive differences in cavitation resistance in C. rhomboidea trees. The only distinct anatomical difference found between internodes was the pith size, with the average pith to xylem area in long internodes, 5x greater than in short internodes. Understanding whether this trade-off exists within and between species will help us to uncover what drives and limits drought resistance across the world's flora.

Restructuring plant types for developing tailor-made crops.

Plants have adapted to different environmental niches by fine-tuning the developmental factors working together to regulate traits. Variations in the developmental factors result in a wide range of quantitative variations in these traits that helped plants survive better. The major developmental pathways affecting plant architecture are also under the control of such pathways. Most notable are the CLAVATA-WUSCHEL pathway regulating shoot apical meristem fate, GID1-DELLA module influencing plant height and tillering, LAZY1-TAC1 module controlling branch/tiller angle and the TFL1-FT determining the floral fate in plants. Allelic variants of these key regulators selected during domestication shaped the crops the way we know them today. There is immense yield potential in the 'ideal plant architecture' of a crop. With the available genome-editing techniques, possibilities are not restricted to naturally occurring variations. Using a transient reprogramming system, one can screen the effect of several developmental gene expressions in novel ecosystems to identify the best targets. We can use the plant's fine-tuning mechanism for customizing crops to specific environments. The process of crop domestication can be accelerated with a proper understanding of these developmental pathways. It is time to step forward towards the next-generation molecular breeding for restructuring plant types in crops ensuring yield stability.

High-quality genome assembly and comparative genomic profiling of yellowhorn (Xanthoceras sorbifolia) revealed environmental adaptation footprints and seed oil contents variations.

Yellowhorn (Xanthoceras sorbifolia) is a species of deciduous tree that is native to Northern and Central China, including Loess Plateau. The yellowhorn tree is a hardy plant, tolerating a wide range of growing conditions, and is often grown for ornamental purposes in parks, gardens, and other landscaped areas. The seeds of yellowhorn are edible and contain rich oil and fatty acid contents, making it an ideal plant for oil production. However, the mechanism of its ability to adapt to extreme environments and the genetic basis of oil synthesis remains to be elucidated. In this study, we reported a high-quality and near gap-less yellowhorn genome assembly, containing the highest genome continuity with a contig N50 of 32.5 Mb. Comparative genomics analysis showed that 1,237 and 231 gene families under expansion and the yellowhorn-specific gene family NB-ARC were enriched in photosynthesis and root cap development, which may contribute to the environmental adaption and abiotic stress resistance of yellowhorn. A 3-ketoacyl-CoA thiolase (KAT) gene (Xso_LG02_00600) was identified under positive selection, which may be associated with variations of seed oil content among different yellowhorn cultivars. This study provided insights into environmental adaptation and seed oil content variations of yellowhorn to accelerate its genetic improvement.

Heterologous expression of SpsLAZY1a in Populus enhanced the sensitiveness of plant architecture

Plant tiller angle is a key agronomic trait that contributes to ideal plant architecture and grain production. However, the molecular mechanism regulating branch angle and plant architecture has not been fully explored in Salix psammophila. Here, we found that the natural germplasm of S. psammophila has a different plant architecture and determined that SpsLAZY1a participated in the control of agronomical traits. SpsLAZY1a was mainly expressed in the stem. SpsLAZY1a transformed with heterologous overexpression in poplar caused distortion at the base of the stem, increased the number of branches and influenced the sensitivity to gravity of the plant. Furthermore, SpsLAZY1a overexpression plants accumulated less auxin and cytokinin than the control. Transcriptome sequencing showed that the overexpression of SpsLAZY1a caused the differential expression of related genes in the plant hormone signal transduction, starch and sucrose metabolism pathways. The expression level of SpsLAZY1a can be rapidly induced by auxin. Taken together, we discovered the key genes related to S. psammophila plant architecture, which provided a basis for further research on the development of tree architecture.

Auxin regulation on crop: from mechanisms to opportunities in soybean breeding.

Breeding crop varieties with high yield and ideal plant architecture is a desirable goal of agricultural science. The success of "Green Revolution" in cereal crops provides opportunities to incorporate phytohormones in crop breeding. Auxin is a critical phytohormone to determine nearly all the aspects of plant development. Despite the current knowledge regarding auxin biosynthesis, auxin transport and auxin signaling have been well characterized in model Arabidopsis (Arabidopsis thaliana) plants, how auxin regulates crop architecture is far from being understood, and the introduction of auxin biology in crop breeding stays in the theoretical stage. Here, we give an overview on molecular mechanisms of auxin biology in Arabidopsis, and mainly summarize auxin contributions for crop plant development. Furthermore, we propose potential opportunities to integrate auxin biology in soybean (Glycine max) breeding.

Natural variation in Tiller Number 1 affects its interaction with TIF1 to regulate tillering in rice.

Tiller number per plant-a cardinal component of ideal plant architecture-affects grain yield potential. Thus, alleles positively affecting tillering must be mined to promote genetic improvement. Here, we report a Tiller Number 1 (TN1) protein harbouring a bromo-adjacent homology domain and RNA recognition motifs, identified through genome-wide association study of tiller numbers. Natural variation in TN1 affects its interaction with TIF1 (TN1 interaction factor 1) to affect DWARF14 expression and negatively regulate tiller number in rice. Further analysis of variations in TN1 among indica genotypes according to geographical distribution revealed that low-tillering varieties with TN1-hapL are concentrated in Southeast Asia and East Asia, whereas high-tillering varieties with TN1-hapH are concentrated in South Asia. Taken together, these results indicate that TN1 is a tillering regulatory factor whose alleles present apparent preferential utilization across geographical regions. Our findings advance the molecular understanding of tiller development.

Ectopic Expression of PvHMA2.1 Enhances Cadmium Tolerance in Arabidopsis thaliana

Cadmium (Cd) in soil inhibits plant growth and development and even harms human health through food chain transmission. Switchgrass (Panicum virgatum L.), a perennial C4 biofuel crop, is considered an ideal plant for phytoremediation due to its high efficiency in removing Cd and other heavy metals from contaminated soil. The key to understanding the mechanisms of switchgrass Cd tolerance is to identify the genes involved in Cd transport. Heavy-metal ATPases (HMAs) play pivotal roles in heavy metal transport, including Cd, in Arabidopsis thaliana and Oryza sativa, but little is known about the functions of their orthologs in switchgrass. Therefore, we identified 22 HMAs in switchgrass, which were distributed on 12 chromosomes and divided into 4 groups using a phylogenetic analysis. Then, we focused on PvHMA2.1, which is one of the orthologs of the rice Cd transporter OsHMA2. We found that PvHMA2.1 was widely expressed in roots, internodes, leaves, spikelets, and inflorescences, and was significantly induced in the shoots of switchgrass under Cd treatment. Moreover, PvHMA2.1 was found to have seven transmembrane domains and localized at the cell plasma membrane, indicating that it is a potential transporter. The ectopic expression of PvHMA2.1 alleviated the reduction in primary root length and the loss of fresh weight of Arabidopsis seedlings under Cd treatment, suggesting that PvHMA2.1 enhanced Cd tolerance in Arabidopsis. The higher levels of relative water content and chlorophyll content of the transgenic lines under Cd treatment reflected that PvHMA2.1 maintained water retention capacity and alleviated photosynthesis inhibition under Cd stress in Arabidopsis. The roots of the PvHMA2.1 ectopically expressed lines accumulated less Cd compared to the WT, while no significant differences were found in the Cd contents of the shoots between the transgenic lines and the WT under Cd treatment, suggesting that PvHMA2.1 reduced Cd absorption from the environment through the roots in Arabidopsis. Taken together, our results showed that PvHMA2.1 enhanced Cd tolerance in Arabidopsis, providing a promising target that could be engineered in switchgrass to repair Cd-contaminated soil.

Competition for Light Interception in Different Plant Canopy Characteristics of Diverse Cotton Cultivars.

Identifying the ideal plant nature and canopy structure is of great importance for improving photosynthetic production and the potential action of plants. To address this challenge, an investigation was accomplished in 2018 and 2019 at the Institute of Cotton Research (ICR) of the Chinese Academy of Agricultural Science (CAAS), Henan Province, China. Six cotton varieties with diverse maturities and plant canopy structures were used to evaluate the light interception (LI) in cotton, the leaf area index (LAI), the biomass, and the yield throughout the two years of study. The light spatial distribution in the plant canopy was evaluated using a geographic statistical method, following the increasing quantity of radiation intercepted, which was determined using the rules of Simpson. Compared to the cotton plants with a compact structure, varieties with both a loose and tower design captured a comparatively higher amount of light (average 31.3%) and achieved a higher LAI (average 32.4%), eventually achieving a high yield (average 10.1%). Furthermore, the polynomial correlation revealed a positive relationship between the biomass accumulation in the reproductive parts and canopy-accrued light interception (LI), signifying that light interception is critical for the yield development of cotton. Furthermore, when the leaf area index (LAI) was peaked, radiation interception and biomass reached the highest during the boll-forming stage. These findings will provide guidance on the light distribution in cotton cultivars with an ideal plant structure for light capture development, providing an important foundation for researchers to better manage light and canopies.