The all-day pollinator visits of sunflower inflorescences in Helianthus annuus plantations are independent of head orientation: Testing a widespread hypothesis.

Mature inflorescences of sunflowers (Helianthus annuus) orient constantly on average to the geographical east. According to one of the explanations of this phenomenon, the eastward orientation of sunflower inflorescences increases the number of attracted insect pollinators. We tested this hypothesis in three field experiments performed in flowering sunflower plantations. In experiments 1 and 2 we measured the number of insects trapped by the vertical walls of sticky sunflower models facing north, east, south, and west. In experiment 3 we counted the pollinators' landings on real sunflower inflorescences facing naturally east or turned artificially toward north, south, and west. We found that the all-day number of pollinators (predominantly bees) attracted to model and real sunflowers in H. annuus plantations is independent of the azimuth direction of sunflower heads, and after 10 h in the morning, the average number of pollinators counted every 20 min is practically constant in the rest of the day.

Multi-omics-driven advances in the understanding of triacylglycerol biosynthesis in oil seeds.

Vegetable oils are rich sources of polyunsaturated fatty acids and energy as well as valuable sources of human food, animal feed, and bioenergy. Triacylglycerols, which are comprised of three fatty acids attached to a glycerol backbone, are the main component of vegetable oils. Here, we review the development and application of multiple-level omics in major oilseeds and emphasize the progress in the analysis of the biological roles of key genes underlying seed oil content and quality in major oilseeds. Finally, we discuss future research directions in functional genomics research based on current omics and oil metabolic engineering strategies that aim to enhance seed oil content and quality, and specific fatty acids components according to either human health needs or industrial requirements.

Genome-wide identification and characterization of exapted transposable elements in the large genome of sunflower (Helianthus annuus L.).

Transposable elements (TEs) are an important source of genome variability, playing many roles in the evolution of eukaryotic species. Besides well-known phenomena, TEs may undergo the exaptation process and generate the so-called exapted transposable element genes (ETEs). Here we present a genome-wide survey of ETEs in the large genome of sunflower (Helianthus annuus L.), in which the massive amount of TEs, provides a significant source for exaptation. A library of sunflower TEs was used to build TE-specific Hidden Markov Model profiles, to search for all available sunflower gene products. In doing so, 20 016 putative ETEs were identified and further investigated for the characteristics that distinguish TEs from genes, leading to the validation of 3530 ETEs. The analysis of ETEs transcription patterns under different stress conditions showed a differential regulation triggered by treatments mimicking biotic and abiotic stress; furthermore, the distribution of functional domains of differentially regulated ETEs revealed a relevant presence of domains involved in many aspects of cellular functions. A comparative genomic investigation was performed including species representative of Asterids and appropriate outgroups: the bulk of ETEs that resulted were specific to the sunflower, while few ETEs presented orthologues in the genome of all analyzed species, making the hypothesis of a conserved function. This study highlights the crucial role played by exaptation, actively contributing to species evolution.

Genetic control of abiotic stress-related specialized metabolites in sunflower.

BACKGROUND: Abiotic stresses in plants include all the environmental conditions that significantly reduce yields, like drought and heat. One of the most significant effects they exert at the cellular level is the accumulation of reactive oxygen species, which cause extensive damage. Plants possess two mechanisms to counter these molecules, i.e. detoxifying enzymes and non-enzymatic antioxidants, which include many classes of specialized metabolites. Sunflower, the fourth global oilseed, is considered moderately drought resistant. Abiotic stress tolerance in this crop has been studied using many approaches, but the control of specialized metabolites in this context remains poorly understood. Here, we performed the first genome-wide association study using abiotic stress-related specialized metabolites as molecular phenotypes in sunflower. After analyzing leaf specialized metabolites of 450 hybrids using liquid chromatography-mass spectrometry, we selected a subset of these compounds based on their association with previously known abiotic stress-related quantitative trait loci. Eventually, we characterized these molecules and their associated genes. RESULTS: We putatively annotated 30 compounds which co-localized with abiotic stress-related quantitative trait loci and which were associated to seven most likely candidate genes. A large proportion of these compounds were potential antioxidants, which was in agreement with the role of specialized metabolites in abiotic stresses. The seven associated most likely candidate genes, instead, mainly belonged to cytochromes P450 and glycosyltransferases, two large superfamilies which catalyze greatly diverse reactions and create a wide variety of chemical modifications. This was consistent with the high plasticity of specialized metabolism in plants. CONCLUSIONS: This is the first characterization of the genetic control of abiotic stress-related specialized metabolites in sunflower. By providing hints concerning the importance of antioxidant molecules in this biological context, and by highlighting some of the potential molecular mechanisms underlying their biosynthesis, it could pave the way for novel applications in breeding. Although further analyses will be required to better understand this topic, studying how antioxidants contribute to the tolerance to abiotic stresses in sunflower appears as a promising area of research.

Genome-wide identification and in-silico expression analysis of CCO gene family in sunflower (Helianthus annnus) against abiotic stress.

Carotenoid cleavage oxygenases (CCOs) enzymes play an important role in plant growth and development by producing a wide array of apocarotenoids and their derivatives. These compounds are vital for colouring flowers and fruits and synthesizing plant hormones such as abscisic acid and strigolactones. Despite their importance, the gene family responsible for CCO enzymes in sunflowers has not been identified. In this study, we identify the CCO genes of the sunflower plant to fill this knowledge gap. Phylogenetic and synteny analysis indicated that the Helianthus annnus CCO (HaCCO) genes were conserved in different plant species and they could be divided into three subgroups based on their conserved domains. Analysis using MEME tool and multiple sequence alignment identified conserved motifs in the HaCCO gene sequence. Cis-regulatory elements (CREs) analysis of the HaCCO genes indicated the presence of various responsive elements related to plant hormones, development, and responses to both biotic and abiotic stresses. This implies that these genes may respond to plant hormones, developmental cues, and drought stress, offering potential applications in the development of more resistant crops. Genes belonging to the 9-cis-epoxy carotenoid dioxygenases (NCED) subgroups predominantly exhibited chloroplast localization, whereas the genes found in other groups are primarily localized in the cytoplasm. These 21 identified HaCCOs were regulated by 60 miRNAs, indicating the crucial role of microRNAs in gene regulation in sunflowers. Gene expression analysis under drought stress revealed significant up-regulation of HaNCED16 and HaNCED19, genes that are pivotal in ABA hormone biosynthesis. During organ-specific gene expression analysis, HaCCD12 and HaCCD20 genes exhibit higher activity in leaves, indicating a potential role in leaf pigmentation. This study provides a foundation for future research on the regulation and functions of the CCO gene family in sunflower and beyond. There is potential for developing molecular markers that could be employed in breeding programs to create new sunflower lines resistant to biotic and abiotic stresses.

Heritable differences in abundance of bacterial rhizosphere taxa are correlated with fungal necrotrophic pathogen resistance.

Host-microbe interactions are increasingly recognized as important drivers of organismal health, growth, longevity and community-scale ecological processes. However, less is known about how genetic variation affects hosts' associated microbiomes and downstream phenotypes. We demonstrate that sunflower (Helianthus annuus) harbours substantial, heritable variation in microbial communities under field conditions. We show that microbial communities co-vary with heritable variation in resistance to root infection caused by the necrotrophic pathogen Sclerotinia sclerotiorum and that plants grown in autoclaved soil showed almost complete elimination of pathogen resistance. Association mapping suggests at least 59 genetic locations with effects on both microbial relative abundance and Sclerotinia resistance. Although the genetic architecture appears quantitative, we have elucidated previously unexplained genetic variation for resistance to this pathogen. We identify new targets for plant breeding and demonstrate the potential for heritable microbial associations to play important roles in defence in natural and human-altered environments.

Host selection by thrips is affected by the floral volatile profile of sunflower.

Thrips, Frankliniella intonsa, is a highly polyphagous pest with a worldwide distribution. F. intonsa-infested sunflower seeds show marked visual damage. The study findings revealed that significantly more F. intonsa infested confection sunflower compared to oilseed sunflower, via olfactometer bioassay studies, we found that compared with the flower and pollen of oilseed sunflowers, those of confection sunflowers attract F. intonsa. Considering this discrepancy in the preference of F. intonsa on oilseed and confection sunflowers, the volatiles of the flower and pollens of two sunflowers were analysed by gas chromatography-mass spectroscopy. The behavioural responses of F. intonsa were assessed for these compounds using Y-tube bioassays. Geranyl bromide, a unique volatile component of oilseed sunflowers, induced an assertive approach-avoidance behaviour in F. intonsa, whereas the unique component ethyl isovalerate in confection sunflowers attracted F. intonsa. F. intonsa adults demonstrated significant attraction to the blends of confection sunflowers. Furthermore, field verification revealed that intercropping confection and oilseed sunflowers could effectively control F. intonsa. The study provided insights into the chemical cues used by F. intonsa in locating hosts. Therefore, oilseed sunflowers can be used as repellent plants to prevent F. intonsa invasion.

Chromatographic Evaluation and Characterization of Constituents of Sunflower Seed Extract Used as Food Additives.

Sunflower seed extract, an antioxidant agent registered on the List of Existing Food Additives in Japan, was evaluated using HPLC, and three common constituents were detected. These peaks were identified as monocaffeoylquinic acids (3-O-caffeoylquinic acid, 4-O-caffeoylquinic acid, and 5-O-caffeoylquinic acid [chlorogenic acid]). Upon scrutinizing other components, dicaffeoylquinic acids (isochlorogenic acids; 3,4-di-O-caffeoylquinic, 3,5-di-O-caffeoylquinic, and 4,5-di-O-caffeoylquinic acids) were also identified. Structures of two newly isolated compounds were determined to be 3-O-(3S-2-oxo-3-hydroxy-indole-3-acetyl)-5-O-caffeoylquinic and 4-O-(3S-2-oxo-3-hydroxy-indole-3-acetyl)-5-O-caffeoylquinic acids. To identify the components that contribute to the antioxidant activity of sunflower seed extract, we fractionated the food additive sample solution and examined the active fractions for 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. Monocaffeoylquinic and dicaffeoylquinic acids showed high DPPH activity, including their contribution to the antioxidant activity of this food additive. DPPH radical scavenging activity of the new compounds showed almost the same value as that of the positive control, Trolox. Therefore, the contribution of these compounds was also considered.

First Report of Rhizopus arrhizus (syn. R. oryzae) causing Sunflower Head Rot in Arizona, USA.

Sunflower (Helianthus annuus) is an ornamental, edible-seed, and important oil source plant in the USA. In June 2023, head rot was observed in sunflowers grown in an experimental field at Yuma County Cooperative Extension, University of Arizona, AZ (32°42'35.5"N, 114°42'25.0"W). The disease incidence was of >70%. Head lesions were dark-brown and extended through the head to the bracts and stem. White to gray mycelia and black sporangia-like structures were also observed on sunflower heads. Symptomatic plants (n =10) were sampled to determine the disease causing agent. Five symptomatic tissues for each plant (0.5 to 1 cm) were submitted to surface sterilization by dipping in 75% ethanol 2min, 1% NaOCl for 2 mins and rinsing with sterile water. Once sterilized, the tissues were plated on potato dextrose agar (PDA) plates and incubated at 25±0.2 °C. After two days, hyaline mycelia were observed on PDA which turned white after 7 days. A total of 50 isolates were obtained, of which ten were randomly selected and purified by the hyphal-tip method and later used for morphological analysis. Microscopic observations revealed hyaline and aseptate hyphae, sporangiophores measuring 900 to 1.2000 µm in length and dark-brown sporangium (72 to 144 µm, mean = 90). The columella was sub-globose, and the sporangiospores ranged from 7.29 to 9.37 µm in size (mean = 7.5 µm). The morphological characteristics described above were similar for the ten isolates and were in accordance with the species R. arrhizus as described by (Gryganskyi et al. 2018). Genomic DNA was extracted from three randomly chosen isolates using The DNeasy Plant kit (Qiagen) and used for further molecular identification. The internal transcribed spacer (ITS) region was amplified using ITS1/ITS4 primers (White et al. 1990) and then Sanger sequenced. The sequences shared 100% nucleotide identity with each other (GenBank accession numbers PP747852, PP747853 and PP747854) and shared 100% identity to R. arrhizus GenBank accessions (MT316366.1, MN547407.1). One isolate, YPHC-94-A, was randomly selected for Phylogenetics and Pathogenicity analyses. Phylogenetics analysis based on sequence data of ITS showed that the isolated YPHC-94-A clustered together with R. arrhizus species (Zhang. 2023). Pathogenicity test was conducted by inoculating four sunflower varieties (American giant, Lemon queen, Solar eclipse and Mammoth) (n = 12 for each variety). Plant heads were inoculated with a disc of mycelia (0.5 cm2) and incubated for 24 h at 30 ±2 °C and 94% RH. Five uninoculated plants of each variety were used as controls. Head rot symptoms were observed within 3-5 days on inoculated plant post inoculation depending on the variety, whereas the control plants stayed asymptomatic. R. arrhizus was re-isolated from all the inoculated plants and was morphologically and molecularly identical to the field isolates, thus fulfilling Koch's postulates. R. arrhizus has already been reported in different US regions (Sanogo et al. 2010), however, to the best of our knowledge this is the first report in Arizona. Due the high disease incidence and pathogen aggressiveness found in the environmental conditions of the U.S southwest desert, we consider sunflower Head rot a potential risk for sunflower production in Arizona as well as the large population of wild sunflowers in the State.

Effect of Fungicide and Timing of Application on Management of Phoma Black Stem of Cultivated Sunflowers in the United States.

Phoma black stem (PBS), caused by Phoma macdonaldii Boerema (teleomorph Leptosphaeria lindquistii Frezzi), is the most common stem disease of sunflower (Helianthus annuus L.) in the northern Great Plains region of the United States. However, the impact of PBS on sunflower yield in the United States is unclear, and a near complete absence of information on the impact of fungicides on disease management exists. The objectives of this study were to determine the impact of PBS on sunflower yield, the efficacy of available fungicides, the optimal fungicide application timing, and the economic viability of fungicides as a management tool. Fungicide timing efficacy was evaluated by applying single and/or sequential applications of pyraclostrobin fungicide at three sunflower growth stages in 10 field trials between 2017 and 2019. Efficacy of 10 fungicides from the Fungicide Resistance Action Committee (FRAC) groups 3, 7, and 11 were evaluated in four field trials between 2018 and 2019. The impact of treatments on PBS were evaluated by determination of incidence, severity, maximum lesion height, disease severity index (DSI), and harvested yield. Nine of the 10 fungicides evaluated and all fungicide timings that included an early bud application resulted in disease reductions when compared with the nontreated controls. The DSI was negatively correlated to sunflower yield in high-yield environments (P = 0.0004; R2 = 0.3425) but not in low- or moderate-yield environments. Although FRAC 7 fungicides were generally most efficacious, the sufficient efficacy and lower cost of FRAC 11 fungicides make them more economically viable in high-yielding environments at current market conditions.

Cadmium and zinc accumulation and tolerance in two Egyptian cultivars (S53 and V120) of Helianthus annuus L. as potential phytoremediator.

One of the most important oil crops in the world, sunflower (Helianthus annuus L.), is recognized to help in soil phytoremediation. Heavy metal (HM) contamination is one of the most abiotic challenges that may affect the growth and productivity of such an important crop plant. We studied the influence of HM-contaminated soils on metal homeostasis and the potential hypertolerance mechanisms in two sunflower Egyptian cultivars (V120 and S53). Both cultivars accumulated significantly higher cadmium concentrations in their roots compared to their shoots during Cd and Zn/Cd treatments. Higher root concentrations of 121 mg g-1 dry weight (DW) and 125 mg g-1 DW were measured in V120 plants compared to relatively lower values of 111 mg g-1 DW and 105 mg g-1 DW in the roots of S53 plants, respectively. Cadmium contamination significantly upregulated the expression of heavy metal ATPases (HaHMA4) in the shoots of V120 plants. On the other hand, their roots displayed a notable expression of HaHMA3. This study indicates that V120 plants accumulated and sequestered Cd in their roots. Therefore, it is advised to cultivate the V120 cultivar in areas contaminated with heavy metals as it is a promising Cd phytoremediator.

The current study confirms and provides new insights into the low Cd and Zn concentration responses of two cultivars of Helianthus annuus as potential HM phytoremediators. HMA3 and HMA4 mediated both root sequestration and reduced root-to-shoot translocation rates. Moreover, high CAT and POX activities may reduce oxidative damage and enhance plant tolerance. The V120 showed higher levels of Cd accumulation in its roots and could be a promising cultivar for the phytoremediation of this heavy metal. This work recalls that Cd tolerance is a trait that may vary among cultivars of the same species and should be taken into consideration in the phytomanagement of heavy metals in contaminated soils.

Genome-Wide Identification and Expression Analysis of TGA Family Genes Associated with Abiotic Stress in Sunflowers (Helianthus annuus L.).

Sunflower (Helianthus annuus L.) is an important, substantial global oil crop with robust resilience to drought and salt stresses. The TGA (TGACG motif-binding factor) transcription factors, belonging to the basic region leucine zipper (bZIP) family, have been implicated in orchestrating multiple biological processes. Despite their functional significance, a comprehensive investigation of the TGA family's abiotic stress tolerance in sunflowers remains elusive. In the present study, we identified 14 TGA proteins in the sunflower genome, which were unequally distributed across 17 chromosomes. Employing phylogenetic analysis encompassing 149 TGA members among 13 distinct species, we revealed the evolutionary conservation of TGA proteins across the plant kingdom. Collinearity analysis suggested that both HaTGA01 and HaTGA03 were generated due to HaTGA08 gene duplication. Notably, qRT-PCR analysis demonstrated that HaTGA04, HaTGA05, and HaTGA14 genes were remarkably upregulated under ABA, MeJA, and salt treatments, whereas HaTGA03, HaTGA06, and HaTGA07 were significantly repressed. This study contributes valuable perspectives on the potential roles of the HaTGA gene family under various stress conditions in sunflowers, thereby enhancing our understanding of TGA gene family dynamics and function within this agriculturally significant species.

Evaluation of Zn Uptake by Helianthus annuus, in a Tropical Climate, Using Different Phytoremediation Strategies.

Phytoremediation is a rapidly expanding process due to its technical and economic viability. The objective of this work was to evaluate the phytoremediation potential of Helianthus annuus in three cultivation media: artificially contaminated Catalão soil, hydroponics and roadside soil. In hydroponics, ZnCl2 doses 0.32 mgL- 1, 29.94 mgL- 1, 60.06 mgL- 1, 119.94 mgL- 1 were used. While in the artificially contaminated soil, the doses were 0 mgkg- 1, 299 mgkg- 1, 599 mgkg- 1, 1498 mgkg- 1. Physiological analyzes made it possible to demonstrate that treatments T3 and T4, with the highest concentrations of the metal, inhibited growth and promoted darkening of the roots. The highest Zn contents occurred in the aerial part. The results indicated that Helianthus annuus was classified as hyperaccumulator due to its ability to accumulate high levels of Zn mainly in artificially contaminated soil.

A seed-specific transcription factor, HSFA9, anticipates UV-B light responses by mimicking the activation of the UV-B receptor in tobacco.

Sunflower heat shock factor A9 (HSFA9, hereafter A9) is a transcription factor involved in seed desiccation tolerance and longevity. A9 also links the regulation of seed maturation with that of seedling photomorphogenesis through visible light receptors. Analyses in transgenic Nicotiana tabacum (tobacco) indicated that A9 also affects responses mediated by NtUVR8, the receptor of ultraviolet light B (UV-B). We compared the effects of A9 and UV-B illumination on the nuclear localization of GFP-NtUVR8 in Nicotiana benthamiana leaves. We also used co-immunoprecipitation and limited proteolysis for analyzing the interaction between A9 and NtUVR8. We found that A9, by binding to NtUVR8, induced structural changes that resulted in enhancing the nuclear localization of NtUVR8 by hindering its nuclear export. The localization of UVR8 is crucial for receptor activation and function in Arabidopsis, where UV-B-activated nuclear UVR8 binds the E3 ubiquitin ligase COP1, leading to enhanced UV-B responses and photoprotection. A9 similarly activated NtUVR8 by enhancing COP1 binding without UV-B light. Seedlings and dark-germinated seeds that overexpress A9 showed primed UV-B light stress protection. Our results unveil a UV-B-independent activation mechanism and a role for UVR8 in plant seeds that might contribute to early stress protection, facilitating seedling establishment.

Sunflower plantings reduce a common gut pathogen and increase queen production in common eastern bumblebee colonies.

Community diversity can reduce the prevalence and spread of disease, but certain species may play a disproportionate role in diluting or amplifying pathogens. Flowers act as both sources of nutrition and sites of pathogen transmission, but the effects of specific plant species in shaping bee disease dynamics are not well understood. We evaluated whether plantings of sunflower (Helianthus annuus), whose pollen reduces infection by some pathogens when fed to bees in captivity, lowered pathogen levels and increased reproduction in free-foraging bumblebee colonies (Bombus impatiens). Sunflower abundance reduced the prevalence of a common gut pathogen, Crithidia bombi, and reduced infection intensity, with an order of magnitude lower infection intensity at high sunflower sites compared with sites with little to no sunflower. Sunflower abundance was also positively associated with greater queen production in colonies. Sunflower did not affect prevalence of other detected pathogens. This work demonstrates that a single plant species can drive disease dynamics in foraging B. impatiens, and that sunflower plantings can be used as a tool for mitigating a prevalent pathogen while also increasing reproduction of an agriculturally important bee species.

Resurrecting urban sunflowers: Phenotypic and molecular changes between antecedent and modern populations separated by 36 years.

Resurrection experiments provide a unique opportunity to evaluate phenotypic and molecular evolution in response to environmental challenges. To understand the evolution of urban populations of Helianthus annuus, we compared plants from 36-year-old antecedent seed collections to modern seed collections from the same area using molecular and quantitative genetic approaches. We found 200 differentially expressed transcripts between antecedent and modern groups, and transcript expression was generally higher in modern samples as compared to antecedent samples. Admixture analysis indicated gene flow from domesticated to modern populations over time. After a greenhouse refresher generation, one antecedent-modern population pair was grown under two water availability (well-watered and drought) and temperature (ambient and elevated by 2.8°C) conditions reflecting historical and contemporary climates. Overall, 78% (7 out of 9) of traits differed between the antecedent and modern populations, with modern individuals displaying some trait changes that are coherent with climate changes expectations and some trait changes in the direction of crop varieties. Phenotypic selection analysis showed that modern trait values were often favoured by selection, especially in environmental treatments resembling modern conditions. Trait heritability in the antecedent population was five times as high as in the modern population, on average. In addition, phenotypic plasticity for some traits, such as flowering phenology, was present in the antecedent population but absent in the modern population. The combination of phenotypic and molecular information suggests that evolution has been influenced by crop-wild introgression, adaptive processes and drift. We discuss these results in the context of continued evolution in response to anthropogenic factors.

Hydraulic integrity of plant organs during drought stress and recovery in herbaceous and woody plant species.

The relationship between root, stem, and leaf hydraulic status and stomatal conductance during drought (field capacities: 100-25%) and drought recovery was studied in Helianthus annuus and five tree species (Populus×canadensis, Acer saccharum, A. saccharinum, Picea glauca, and Tsuga canadensis). Measurements of stomatal conductance (gs), organ water potential, and vessel embolism were performed and the following was observed: (i) cavitation only occurred in the petioles and not the roots or stems of tree species regardless of drought stress; (ii) in contrast, all H. annuus organs exhibited cavitation to an increasing degree from root to petiole; and (iii) all species initiated stomatal closure before cavitation events occurred or the expected turgor loss point was reached. After rewatering: (i) cavitated vessels in petioles of Acer species recovered whereas those of P. ×canadensis did not and leaves were shed; (ii) in H. annuus, cavitated xylem vessels were refilled in roots and petioles, but not in stems; and (iii) despite refilled embolisms in petioles of some species during drought recovery, gs never returned to pre-drought conditions. Conclusions are drawn with respect to the hydraulic segmentation hypothesis for above- and below-ground organs, and the timeline of embolism occurrence and repair is discussed.

Safety Assessment of Helianthus annuus (Sunflower)-Derived Ingredients as Used in Cosmetics.

This is a review of the scientific literature and unpublished data that are relevant for assessing the safety of 12 Helianthus annuus (sunflower)-derived ingredients as used in cosmetics. Because final product formulations may contain multiple botanicals, each containing similar constituents of concern, formulators are advised to be aware of these constituents and to avoid levels that may be hazardous to consumers. Helianthus annuus (sunflower)-derived ingredients may contain allergens, including 2S albumins and sesquiterpene lactones. Industry should use current good manufacturing practices (cGMP) to limit impurities and constituents of concern. The Expert Panel for Cosmetic Ingredient Safety (Panel) concluded that 9 Helianthus annuus (sunflower) seed- and flower-derived ingredients are safe as used in cosmetics in the present practices of use and concentration described in this safety assessment. The data are insufficient to evaluate the safety of 3 ingredients that are derived from other plant parts.

Phytoaccumulation of zinc from contaminated soil using ornamental plants species Helianthus annuus L. and Tagetes erecta L.

Intensive research on hyperaccumulator plant species provides an alternative method to cleanup heavy metal contaminated sites using these plants. Helianthus annuus and Tagetes erecta are suitable hyperaccumulator plant species for removing zinc (Zn) from contaminated soil because of their high phytoremediation effectiveness. The present study focused on to evaluate comparative efficacy of Zn accumulation using H. annuus and T. erecta. Plantlets were exposed to different Zn concentrations (10, 50, 100, 300, and 500 mg kg-1) for 20, 40, and 60 days while changes in morphological, biochemical, and enzyme activity markers were evaluated. The concentration of Zn in various plant parts was determined using an atomic absorption spectrophotometer (AAS). After 60 days H. annuus showed greatest accumulation of Zn in the root and shoot (216.7 and 109.5 mg kg-1), whereas the Zn accumulation T. erecta (209.5 and 97.84 mg kg-1) was found comparatively less in the root and shoot. The result showed increased polyphenol and proline concentrations with increasing Zn concentrations which were maximal in H. annuus 6.642 mg g-1 and 25.474 µmol g-1, respectively. At 60 days, APX (4.145 mM mg-1), CAT (2.558 mM mg-1), and GR (52.23 mM mg-1) antioxidant enzymatic activities were observed with higher concentrations. Analysis of ultrastructure confirmed Zn transport and localization in root and shoot tissues examined through FESEM-EDX, Fluorescence microscopy, and optical microscopy. The present research findings concluded with the high amount of removal of Zn from contaminated soil using H. annuus and T. erecta for ecofriendly approach to soil cleanup followed by sustainable agriculture.

Our research work focused on the removal of zinc from the contaminated soil by phytoremediation using ornamental plants species Helianthus annuus and Tagetes erecta. Our research findings through detailed microscopic observation, antioxidant analysis, and biochemical evaluation have proven that Helianthus annuus L. have a better capability for Zn mitigation in the contaminated site as compared to Tagetes erecta. As an outcome of this research, we authentically suggest for use of H. annuus as a good accumulator of Zn compared to T. erecta.

Genome-Wide Analysis of WOX Multigene Family in Sunflower (Helianthus annuus L.).

The WUSCHEL-related homeobox (WOX) is a family of specific transcription factors involved in plant development and response to stress, characterized by the presence of a homeodomain. This study represents the first comprehensive characterization of the WOX family in a member of the Asteraceae family, the sunflower (H. annuus L.). Overall, we identified 18 putative HaWOX genes divided by phylogenetic analysis in three major clades (i.e., ancient, intermediate, and WUS). These genes showed conserved structural and functional motifs. Moreover, HaWOX has homogeneously distributed on H. annuus chromosomes. In particular, 10 genes originated after whole segment duplication events, underpinning a possible evolution of this family along with the sunflower genome. In addition, gene expression analysis evidenced a specific pattern of regulation of the putative 18 HaWOX during embryo growth and in ovule and inflorescence meristem differentiation, suggesting a pivotal role for this multigenic family in sunflower development. The results obtained in this work improved the understanding of the WOX multigenic family, providing a resource for future study on functional analysis in an economically valuable species such as sunflower.