Lifespan Of Plant Research Articles

Operational Flexibility Evaluation and Techno-Economic Analysis on Hot Primary Air Temperature Boosting by Reheated Steam in a Lignite-Fired Power Plant

Abstract Coal-fired power plants are commonly used as adjustable power sources to complement the fluctuating output of wind and solar energy. The investigation is required to determine the flexible peak-shaving capabilities of coal-fired boilers. A modified scheme for a lignite-fired power plant to further improve the primary air temperature using the outlet steam from the low-temperature reheater is studied while increasing the inlet flue gas temperature of the air preheater is considered the conventional scheme. Thermodynamic models of the power plant are constructed using ebsilon software. The operational characteristics of both schemes are compared under 30% turbine heat acceptance (THA)–100%THA conditions and the economic performance of the modified scheme is also evaluated. Results indicate that the modified scheme exhibits superior thermodynamic and economic performances compared to the conventional scheme. The disparity in power generation efficiency between the conventional and modified schemes reaches a maximum of 0.23 percentage points under 75%THA conditions. The net present value of the modified scheme amounts to 4.51 million dollars over the power plant lifespan of 30 years. The modified scheme allows the conventional denitrification catalyst to maintain an optimal temperature range even under 30%THA conditions, resulting in a power generation efficiency only 4.8 percentage points lower than that under 100%THA conditions, thus demonstrating remarkable operational flexibility. This study presents an efficient, cost-effective, and adaptable approach for lignite-fired power plants.

A joint economic evaluation and FP2O techno-economic resilience approach for evaluation of suspension PVC production

The production of polyvinyl chloride (PVC) involves obtaining a thermoplastic polymer from vinyl chloride monomer (VCM) and ethylene, primarily through the suspension method. This process is vital for manufacturing various products, such as pipes and coatings. However, its high-energy consumption necessitates economic evaluations to assess feasibility. In this work, a dual approach is proposed: a Feedstock-Processing-Product-Operation (FP2O) based techno-economic resilience analysis via sensitivity analysis alongside economic evaluation. The study evaluated a PVC production process with a capacity of 518,400 t/y of VCM over a 15-year plant lifespan. The techno-economic assessment revealed a Total Capital Investment of $609, 882, 203, a Payback Period of 4.22 years, and a Return on Investment of 14.38 %. Positive Net Present Value and a cost/benefit ratio >1 indicate the plant's installation under proposed conditions is favorable. Additionally, the technical-economic resilience analysis identified the process's response to changes in PVC price, raw material costs, and production capacity, guiding improvement actions pre- and post-plant assembly.

Pervasive impacts of railway edge effects on edaphic parameters and vegetation distribution patterns

Addressing the ecological impacts of transport corridors while planning any transport network is paramount for a better of understanding ecological processes, biodiversity distribution, and ecosystem resilience. Here, we evaluated the impacts of railway edges on edaphic parameters, plant diversity, and composition in the northwestern Himalaya as a function of perpendicular distance from the railway track. In 2014 and 2017, we sampled vegetation plots across 31 sites distributed along 119 km of the Kashmir railway to test the effect of railway tracks on edaphic and vegetative parameters in short-term periods. T-shaped plots were laid comprising four sub-plots, one parallel to the track and the other three perpendiculars to it. We adopted the Mountain Invasion Research Network road survey methodology for data collection. We found (i) an increasing trend in all soil parameters (electrical conductivity, salinity, organic carbon, available nitrogen, and available phosphorus), except pH, as the distance from the railway track increased; (ii) significant railway edge effects on the importance value index of plant growth forms, life span, nativity and taxonomic group across space (distance of plots from the track) and time (2014–2017); and (iii) a significant spatiotemporal railway edge effects on plant species composition. Our results are pioneering in showing that railway tracks crossing through different ecosystems alter the edaphic conditions, resulting in direct and indirect edge effects on key abiotic and biotic factors, which in turn impact the vegetation of the surrounding natural habitats on both sides of the railway track. Our study contributes toward a better understanding of the role of anthropogenic edges like railways on edaphic parameters and vegetation distribution.

Soil Seed Bank of the Alpine Endemic Carnation, Dianthus pavonius Tausch (Piedmont, Italy), a Useful Model for the Study of Host-Pathogen Dynamics.

Soil seedbanks are particularly important for the resiliency of species living in habitats threatened by climate change, such as alpine meadows. We investigated the germination rate and seedbank potential for the endemic species Dianthus pavonius, a carnation native to the Maritime Alps that is used as model system for disease in natural populations due to its frequent infections by a sterilizing anther-smut pathogen. We aimed to ascertain whether this species can create a persistent reserve of viable seeds in the soil which could impact coevolutionary dynamics. Over three years, we collected data from seeds sown in natural soil and analyzed their germination and viability. We found that D. pavonius seeds are not physiologically dormant and they are able to create a persistent soil seed bank that can store seeds in the soil for up to three years, but lower than the estimated plant lifespan. We conclude that while the seedbank may provide some demographic stability to the host population, its short duration is unlikely to strongly affect the host's ability to respond to selection from disease. Our findings have implications for the conservation of this alpine species and for understanding the evolutionary dynamics between the host and its pathogen.

Accelerate Senescence Reversed CO2‐Fertilization Effect under Elevated CO2 in Potato: A Weak Relationship with Nitrogen Acquisition

ABSTRACTAccelerated senescence under elevated CO2 (eCO2) has not received sufficient attention, and its impact on the effect of CO2‐fertilization is unclear. To investigate the relationship between plant senescence and CO2 concentration, a pot experiment was conducted in four potato genotypes under low CO2 (LC), medium CO2 (MC) and high CO2 (HC) conditions. Nitrogen (N) uptake and cumulative transpiration were analysed to clarify whether eCO2‐induced senescence could be explained by low N uptake due to reduced transpiration. Compared to LC, the lifespan of potato plants under MC and HC was reduced by 3%–6% and 12%–32%, respectively, depending on the genotype. Biomass accumulation at full senescence was reduced when lifespan was shortened by approximately 5% and 10% under MC and HC, respectively. Cumulative transpiration was less affected by eCO2 during early developmental stages but decreased under eCO2 as plants aged. Plant water use decreased with a shortened lifespan under eCO2, but there was no reduction in N uptake, which was attributed to the high N uptake per unit of water used. The results of this study indicate that senescence in potato genotypes is non‐linearly related to CO2 concentration and cannot be explained by reduced N acquisition via reduced transpiration. The positive effect of CO2 fertilization can be reversed by accelerated senescence under eCO2.

A tomato B-box protein regulates plant development and fruit quality through the interaction with PIF4, HY5, and RIN transcription factors.

During the last decade, knowledge about BBX proteins has greatly increased. Genome-wide studies identified the BBX gene family in several ornamental, industry, and food crops; however, reports regarding the role of these genes as regulators of agronomically important traits are scarce. Here, by phenotyping a knockout mutant, we performed a comprehensive functional characterization of the tomato locus Solyc12g089240, hereafter called SlBBX20. The data revealed the encoded protein as a positive regulator of light signaling affecting several physiological processes during the life span of plants. Through inhibition of PHYTOCHROME INTERACTING FACTOR 4 (SlPIF4)-auxin crosstalk, SlBBX20 regulates photomorphogenesis. Later in development, it controls the balance between cell division and expansion to guarantee correct vegetative and reproductive development. In fruits, SlBBX20 is transcriptionally induced by the master transcription factor RIPENING INHIBITOR (SlRIN) and, together with ELONGATED HYPOCOTYL 5 (SlHY5), up-regulates flavonoid biosynthetic genes. Finally, SlBBX20 promotes the accumulation of steroidal glycoalkaloids and attenuates Botrytis cinerea infection. This work clearly demonstrates that BBX proteins are multilayer regulators of plant physiology because they affect not only multiple processes during plant development but they also regulate other genes at the transcriptional and post-translational levels.

Two key enzyme genes associated with ethylene bio-synthesis, LbACS and LbACO, are involved in the regulation of lily flower senescence

Ethylene plays an important role in regulating the growth and development of flowers and determines the flower life span of ornamental plants. In this study, the lily variety 'Manissa' was used to elucidate the mechanism associated with the regulation of lily senescence by the genes for 1-aminocyclopropane-1-carboxylic acid synthetase (ACS) and 1-aminocyclopropane-1-carboxylic acid oxidase (ACO), which are key enzymes in the ethylene biosynthesis pathway. The results showed that ethylene release increased, the relative water content first increased and then decreased, and relative conductivity continuously increased as lily bud development progressed. LbACS1 transcription was highest at the blooming stage, LbACS7 transcription was highest at the green bud stage, and LbAC03 and LbAC04 levels both peaked at the yellow bud stage and the blooming stage. After treating cut lily flowers with ethephon and ethylene inhibitor 1-methylcyclopropene (1-MCP), the results showed that ethephon promoted the senescence of cut flowers, ethylene release, and the transcription levels of the four Lb genes. 1-MCP treatment also delayed the aging of cut flowers, but reduced ethylene release and inhibited the transcription of LbAC03 and LbAC04 when the treatment was applied during the later stages of bud development. This study provided evidence for the role of ethylene and the functions of LbACS and LbAC0 in the aging process associated with cut lily flowers.

Optimizing Energy Efficiency: An Integrated Life Cycle Costing Approach for Centralized Cooling Plants

Gas District Cooling (GDC) is an emerging technology utilizing natural gas-based systems for efficient district-scale cooling. This study develops a comprehensive Life Cycle Costing (LCC) model integrating capital expenditure (CAPEX) and operational expenditure (OPEX) for Thermal Energy Storage (TES) and Electrical Chillers (ECs) within GDC plants. Validated through a case study at an academic institute's GDC plant in Malaysia, the model assesses breakeven scenarios, revealing that project feasibility is optimal under case-II conditions, emphasizing the importance of operational efficiency for sustained economic viability throughout the plant's lifespan. These insights enhance understanding of financial considerations and investment strategies for adopting GDC technology in urban cooling applications, highlighting the need for strategic planning and lifecycle management to optimize economic performance and support broader sustainable development goals. Ongoing research will further refine LCC models, advancing the economic competitiveness of GDC as a key component of sustainable urban cooling solutions.

Linking the rhizosphere effects of 12 woody species on soil microbial activities with soil and root nitrogen status

The rhizosphere effect depicts the changes in soil physical, chemical, and biological properties due to altered microbial activity in response to root activity, which has important implications for soil carbon and nutrient cycling. However, how the plant-induced changes in rhizosphere soil microbial activity correlate with root and soil nutrient status remains uncertain. Here we targeted 12 woody species of distinct growth forms, i.e., tree vs. shrub, in an urban park on a university campus in Beijing, China. We measured root carbon and nitrogen concentrations and soil properties of paired rhizosphere and bulk soils for each plant. We investigated how the rhizosphere effects on microbial properties, as indicated by microbial biomass and potential activity of soil extracellular hydrolases, varied among the 12 woody species and between trees and shrubs, as well as how they were regulated by bulk soil and root nitrogen status. In general, across the 12 species, root nitrogen content, which is a potential indicator of plant life span and nutrient acquisition strategy, was positively correlated with the rhizosphere effect on potential enzyme activity, while the inverse was true for root carbon: nitrogen ratio, which further verified the role of root functional traits in controlling soil nutrient cycling through the rhizosphere effect. Moreover, soil organic carbon, total nitrogen, and available nitrogen concentrations were all found to be negatively correlated with the rhizosphere effect on microbial properties, which highlighted the stimulation of rhizosphere microbial activity for nitrogen acquisition (the nitrogen-mining hypothesis). Trees and shrubs exhibited no significant differences in their rhizosphere effects, and there was a potential difference in the role of rhizosphere effect in regulating soil nitrogen cycling between legumes and non-legumes. Overall, our study highlights the role of plant nutrient acquisition strategy and soil nutrient status in regulating the rhizosphere effect of woody species on microbial-driven soil processes, which is essential for a better understanding of mechanisms by which plants sustain their nutrient supply.

Medullary bundles in Caryophyllales: form, function, and evolution.

The occurrence of conducting vascular tissue in the pith (CVTP) of tracheophytes is noteworthy. Medullary bundles, one of the remarkable examples of CVTP, evolved multiple times across angiosperms, notably in the Caryophyllales. Yet, information on the occurrence of medullary bundles is fragmented, hampering our understanding of their structure-function relationships, and evolutionary implications. Using three plastid molecular markers (matK, rbcL, and rps16 intron), a phylogeny is constructed for 561 species of Caryophyllales, and anatomical data are assembled for 856 species across 40 families to investigate the diversity of medullary bundles, their function, evolution, and diversification dynamics. Additionally, correlated evolution between medullary bundles and successive cambia was tested. Medullary bundles are ancestrally absent in Caryophyllales and evolved in core and noncore families. They are structurally diverse (e.g. number, arrangement, and types of bundles) and functionally active throughout the plant's lifespan, providing increased hydraulic conductivity, especially in herbaceous plants. Acquisition of medullary bundles does not explain diversification rate heterogeneity but is correlated to a higher diversification rate. Disparate developmental pathways were found leading to rampant convergent evolution of CVTP in Caryophyllales. These findings indicate the diversification of medullary bundles and vascular tissues as another central theme for functional and comparative molecular studies in Caryophyllales.

Structural and functional changes in macrophyte species composition in softwater lakes after 60 years of land use

We compared structural and functional changes in macrophyte species composition in softwater lakes with isoetids located along the southern shore of the Baltic Sea (NW Poland) in two time periods (1955–1959 and 2015–2020). The research aimed to determine the trend of changes in macrophyte composition influenced by fields and/or urban fabric, as land use. The land-use pressure measure referred to the volume of land occupied around the lake. In the second time period, the number of plant species in the lakes increased twofold (20 vs. 39), compared to the first period. The average values of species richness were statistically higher (p < 0.001) in the second period (15.7 vs. 8.6). The functional diversity of plants in the lakes revealed statistically significant differences in both periods compared. The FD Rao values calculated for plant life span, growth forms, and FD multi-traits were statistically higher in the second period (p < 0.001). Our findings revealed that the anthropogenic pressure on lakes over a period of 60 years caused a decrease in the share of sensitive species in macrophyte species composition (isoetids and mosses), but an increase in common plants with a completely different set of species functional traits. This is related to the environmental changes that occurred between the two periods studied. First of all, we noticed significant changes in the transparency (visibility) of the water. In the second period, the value of this trait is used in each lake, which uses the transmission of photosynthetic active radiation (PAR) light transmittance to the plant and can affect the species composition. These findings show that an increase in biodiversity can relate to a decrease in freshwater ecosystem function, mainly via lost function of evergreen isoetid species.

Phenology of the Antyllis vulneraria L. in Moscow region

The research topic is the study of the biological characteristics of the local flora protected species Anthillis vulneraria L., under conditions of field experience in the Moscow region. The purpose of this research was to study the phenological cycle and the influence of meteorological factors on the timing and duration of phenophases. In the period from 2017 to 2022, a reduction in the duration of the shoot regrowth period, budding and flowering phases was revealed due to an increase in the sum of average daily temperatures and a decrease in precipitation. The resistance of plants to the conditions of the winter season in plants of the 1st-2nd year is 60-84 %, in plants of the 3rd year 50 %. A. vulneraria goes through a full phenological cycle in 175-190 days, blooms and bears fruit annually, forms a viable self-seeding, starting from the 2nd year of vegetation, grows in one place for up to 6 years, with the lifespan of individual plants up to 3 years. Pre-sowing preparation of seeds - wet stratification for 2 months, increases their germination rate to 53-65 %. The results of the study are relevant for maintaining the number of A. vulneraria that is a protected species of local natural flora in the Moscow region.

Habitat preferences and functional traits drive longevity in Himalayan high‐mountain plants

Plant lifespan has important evolutionary, physiological, and ecological implications related to population persistence, community stability, and resilience to ongoing environmental change impacts. Although biologists have long been puzzled over the extraordinary variation in plant lifespan and its causes, our understanding of interspecific variability in plant lifespan and the key internal and external factors influencing longevity remains limited. Here, we demonstrate the concurrent impacts of environmental, morphological, physiological, and anatomical constraints on interspecific variation in longevity among &gt; 300 vascular dicot plant species naturally occurring at an elevation gradient (2800–6150 m) in the western Himalayas. First, we show that plant longevity (ranging from 1 to 100 years) is largely related to species' habitat preferences. Ecologically stressful habitats such as alpine and subnival host long‐lived species, while productive ruderal and wetland habitats contain a higher proportion of shorter‐lived species. Second, longevity is influenced by growth form with monocarpic forbs having the shortest lifespan and woody shrubs having the highest. Small‐statured cushion plants with compact canopies and deep roots, most found on cold and infertile alpine and subnival soils, had a higher chance of achieving longevity. Third, plant traits reflecting plant adaptations to stress and disturbance affect interspecific differences in plant longevity. We show that longevity and growth are negatively correlated. Slow‐growing species are those that have a higher chance of reaching a high age. Finally, higher longevity was associated with high leaf carbon and phosphorus, low root phosphorus and nitrogen, and with large bark‐xylem ratio. Our findings suggest that plant longevity in high elevation is intricately determined by a combination of habitat preferences and growth form, as well as the plant growth rate and physiological processes.

Comprehensive transcriptomic analysis of age-, dark-, and salt-induced senescence reveals underlying mechanisms and key regulators of leaf senescence in Zoysia japonica.

The lawn grass Zoysia japonica is widely cultivated for its ornamental and recreational value. However, its green period is subject to shortening, which significantly decreases the economic value of Z. japonica, especially for large cultivations. Leaf senescence is a crucial biological and developmental process that significantly influences the lifespan of plants. Moreover, manipulation of this process can improve the economic value of Z. japonica by extending its greening period. In this study, we conducted a comparative transcriptomic analysis using high-throughput RNA sequencing (RNA-seq) to investigate early senescence responses triggered by age, dark, and salt. Gene set enrichment analysis results indicated that while distinct biological processes were involved in each type of senescence response, common processes were also enriched across all senescence responses. The identification and validation of differentially expressed genes (DEGs) via RNA-seq and quantitative real-time PCR provided up- and down-regulated senescence markers for each senescence and putative senescence regulators that trigger common senescence pathways. Our findings revealed that the NAC, WRKY, bHLH, and ARF transcription factor (TF) groups are major senescence-associated TF families that may be required for the transcriptional regulation of DEGs during leaf senescence. In addition, we experimentally validated the senescence regulatory function of seven TFs including ZjNAP, ZjWRKY75, ZjARF2, ZjNAC1, ZjNAC083, ZjARF1, and ZjPIL5 using a protoplast-based senescence assay. This study provides new insight into the molecular mechanisms underlying Z. japonica leaf senescence and identifies potential genetic resources for enhancing its economic value by prolonging its green period.

EFFECTS AND MANAGEMENT PRACTICES OF HEAT STRESS IN MAIZE (ZEA MAYS L.): A REVIEW

A vital crop in various agro-ecological regions, Maize (Zea mays L.) ranks second only to rice in terms of cultivation in Nepal. Although Maize is considered heat resistant, exposing it to the temperature exceeding 37-degree Celsius results in the heat stress reducing its productivity. Threat of global warming is real with the changing climate, studies indicate future heat waves will likely be more severe and persistent, negatively impacting the productivity. Reduced plant height, decreased leaf area, and delayed flowering are some of the consequences of heat stress in maize plants. It disrupts photosynthetic efficiency, damaging photosynthetic machinery, reducing enzyme activity, and impairing chloroplast functioning. Furthermore, heat stress induces ROS causing cell membrane damage, disruption of enzymatic activities, ultimately resulting in stunted plant growth and productivity. During the flowering stage, heat stress reduces the number of florets, impairs silk and grain development, and promotes premature senescence, leading to a shorter plant lifespan and decreased grain yield. Early sowing of maize, effective irrigation and nutrient management can help reduce soil temperature, enhance water use efficiency and minimize heat stress. The adoption of heat-resistant maize varieties and improved breeding techniques is also essential for mitigating the adverse effects of heat stress in maize cultivation. This paper addresses the consequences of heat stress on maize, including effects on growth, photosynthetic characteristics, reactive oxygen species (ROS), reproductive development, premature senescence, and overall grain yield while also exploring strategies for mitigating the impacts of heat stress on maize through agronomic practices and breeding.

MBOA based PV Array Interconnection Scheme for Enlarging the Harvested Power under PS Condition

Massive penetration of Photovoltaic (PV) systems into the electric supply system poses several problems in the current era, as PV systems have become a feasible alternative to non-renewable energy supplies. On the other hand, partial shading (PS) is a critical issue that impacts the production and lifespan of PV plants. The interconnection of PV is an effective approach for dealing with the PS issues. It is accomplished by arranging the PV modules, based on their temperature and shading stages. In this paper, the Modified Butterfly Optimization Algorithm (MBOA) is proposed to reorganise the PV array. Several criteria are used to assess the performance of the proposed algorithm, including mismatch losses, fill factor, power loss, and percent of power enhancement. Furthermore, the achieved results are related to a standard Total-Cross-Tied (TCT), SuDoKu, Competence Square (CS), and Butterfly Optimization Algorithm (BOA). The highest increase in Global Maximum Power (GMP) has been attained by the proposed MBOA corresponding to the TCT array is 35.76% in the short wide shadow arrangement, while the least increase of 6.59% occurs in the short narrow arrangement. The acquired results reveal that the proposed MBOA’s capability and predominance in optimising the shaded array interconnection.

EVOLUTION OF PERICARP SURFACE STRUCTURE IN NEPETA S. S. (LAMIACEAE) AS INFERRED FROM ANALYSIS OF ITS DATA

Nutlet pericarp structure is important in the taxonomy of Lamiaceae (Labiatae) at different taxonomic levels. Within the family it has also been found that variation in pericarp structure is strongly correlated with the phylogenic results obtained from molecular DNA analyses. The genus Nepeta L., with more than 200 species mainly centred in SW Asia, is one of the taxonomically most complex genera within the family. Traditional taxonomic treatments of Nepeta are mainly based on gross morphology. As in other groups of Lamiaceae, pericarp structure provides some of the diagnostic characters in this genus. In order to investigate patterns of pericarp evolution within Nepeta, we used scanning electron microscopy to examine nutlet surfaces and pericarp cross sections and explored variation of these characters against a molecular phylogeny based on ITS sequences. Based on this phylogenetic analysis, Nepeta in its present circumscription is not monophyletic. Evolutionary trends in structure of nutlet pericarps are apparent although they require confirmation with more robust phylogenies. In particular, nutlets with tuberculate/thorny-like pericarp may have evolved once within this genus, in the common ancestor of five of the six subclades identified within Nepeta, and have been lost independently several times. We also show that evolution of tubercules in Nepeta is not related to plant life span. Our results also indicate that more genetic markers (both plastid and nuclear) are necessary to reconstruct a reliable and robust organismal phylogeny.

Volatile Organic Compounds as Mediators of Plant Communication and Adaptation to Climate Change.

Plant volatile organic compounds are the most abundant and structurally diverse plant secondary metabolites. They play a key role in plant lifespan via direct and indirect plant defenses, attracting pollinators, and mediating various interactions between plants and their environment. The ecological diversity and context-dependence of plant-plant communication driven by volatiles are crucial elements that influence plant performance in different habitats. Plant volatiles are also valued for their multiple applications in the food, flavor, pharmaceutical, and cosmetics industries. In the current review, we summarize recent advances that have elucidated the functions of plant volatile organic compounds as mediators of plant interaction at community and individual levels, highlighting the complexities of plant receiver feedback to various signals and cues. This review emphasizes volatile terpenoids, the most abundant class of plant volatile organic compounds, highlighting their role in plant adaptability to global climate change and stress-response pathways that are integral to plant growth and survival. Lastly, we identify research gaps and suggest future research directions. This article is protected by copyright. All rights reserved.

Bulb growth potential is independent of leaf longevity for the spring ephemeral Erythronium americanum Ker-Gawl.

Growth in most spring ephemerals is decreased under warmer temperatures. Although photosynthetic activities are improved at warmer temperatures, leaves senesce earlier, which prevents the bulb from reaching a larger size. A longer leaf life duration during a warm spring, therefore, may improve bulb mass. We tested this hypothesis by modulating leaf life span of Erythronium americanum through the application of Promalin® (PRO; cytokinins and gibberellins) that prolonged or silver thiosulfate (STS) that reduced leaf duration. Gas exchange and chlorophyll fluorescence were measured along with leaf and bulb carbohydrate concentrations. Plants were also pulse labelled with 13CO2 to monitor sugar transport to the bulb. Lower photosynthetic rates and shorter leaf life span of STS plants reduced the amount of carbon that they assimilated during the season, resulting in a smaller bulb compared with control plants. PRO plants maintained their photosynthetic rates for a longer period than control plants, yet final bulb biomass did not differ between them. We conclude that seasonal growth for E. americanum is not limited by leaf life duration under warm growing conditions, but rather by limited sink growth capacity. Under global warming, spring geophytes might be at risk of being reduced in size and, eventually, reproducing less frequently.

Genome-Wide Identification and Characterization of YUCCA Gene Family in Mikania micrantha.

Auxin is a general coordinator for growth and development throughout plant lifespan, acting in a concentration-dependent manner. Tryptophan aminotransferases (YUCCA) family catalyze the oxidative decarboxylation of indole-3-pyruvic acid (IPA) to form indole-3-acetic acid (IAA) and plays a critical role in auxin homeostasis. Here, 18 YUCCA family genes divided into four categories were identified from Mikania micrantha (M. micrantha), one of the world's most invasive plants. Five highly conserved motifs were characterized in these YUCCA genes (MmYUCs). Transcriptome analysis revealed that MmYUCs exhibited distinct expression patterns in different organs and five MmYUCs showed high expression levels throughout all the five tissues, implying that they may play dominant roles in auxin biosynthesis and plant development. In addition, MmYUC6_1 was overexpressed in DR5::GUS Arabidopsis line to explore its function, which resulted in remarkably increased auxin level and typical elevated auxin-related phenotypes including shortened roots and elongated hypocotyls in the transgenic plants, suggesting that MmYUC6_1 promoted IAA biosynthesis in Arabidopsis. Collectively, these findings provided comprehensive insight into the phylogenetic relationships, chromosomal distributions, expression patterns and functions of the MmYUC genes in M. micrantha, which would facilitate the study of molecular mechanisms underlying the fast growth of M. micrantha and preventing its invasion.