Plant Reproductive Biology Research Articles

Application of genome editing in plant reproductive biology: recent advances and challenges.

This comprehensive review underscores the application of genome editing in plant reproductive biology, including recent advances and challenges associated with it. Genome editing (GE) is a powerful technology that has the potential to accelerate crop improvement by enabling efficient, precise, and rapid engineering of plant genomes. Over the last decade, this technology has rapidly evolved from the use of meganucleases (homing endonucleases), zinc-finger nucleases, transcription activator-like effector nucleases to the use of clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (CRISPR/Cas), which has emerged as a popular GE tool in recent times and has been extensively used in several organisms, including plants. GE has been successfully employed in several crops to improve plant reproductive traits. Improving crop reproductive traits is essential for crop yields and securing the world's food supplies. In this review, we discuss the application of GE in various aspects of plant reproductive biology, including its potential application in haploid induction, apomixis, parthenocarpy, development of male sterile lines, and the regulation of self-incompatibility. We also discuss current challenges and future prospects of this technology for crop improvement, focusing on plant reproduction.

Assessing the role of EDTA and SA in mustard under Cd and Pb stress

Phytoextraction is an economically viable and environmentally sustainable method for approaching heavy metal-polluted soils. Pollen grains are notably more susceptible to pollutants compared to other parts of the plant. However, in polluted environments, certain metals like lead (Pb) and cadmium (Cd) may have limited bioavailability, posing significant challenges to the phytoextraction process. One way to overcome this limitation is by employing chelators. The experiment was conducted in a randomized block design to investigate the effects of two chelators, EDTA and salicylic acid (SA), in enhancing the plant water status, biochemicals and reproductive parameters of Brassica juncea seedlings. These seedlings were sown in pots and subjected to various treatments of Cd and Pb of concentrations 10 and 20 mM, either alone or in combination with 0.5 mM EDTA and SA. The toxicity induced by Pb and Cd in B. juncea was recorded through decreased levels of osmotic potential in leaves and roots and decreased leaf chlorophyll content. Additionally, various reproductive parameters, including pollen viability, pollen germination, and in-vitro pollen germination, were highly affected by stress. Conversely, the supplementation of EDTA and SA to Cd, and Pb-treated plants effectively mitigated the negative impact of heavy metal stress by increasing osmotic potential, chlorophyll content, and reproductive parameters. Notably, EDTA and SA also significantly increased Pb and Cd accumulation. The result demonstrates the potential of EDTA and SA in improving plant reproductive biology.

Identifying bottlenecks in the life cycle of plants living on cliffs and rocky slopes: Lack of knowledge hinders conservation actions

Long term survival of plant populations relies on successful reproductive cycle to obtain generation turnover. Focusing on plant species of conservation concern, we brought together a group of plant conservationists from different countries to assess whether the already available information on plant reproductive biology and autecology is adequate for identifying which phases of single species life cycle might act as bottleneck.We compiled a list of 80 plant species of conservation concern living on European cliffs and rocky slopes, for which biological and autecological information was collected from scientific literature, technical reports, and expert knowledge.Results have shown that the available information on species reproductive biology and autecology is inadequate to identify bottlenecks in the life cycle of many species and to provide insights for the practical conservation of many more. Available knowledge is mainly referred to the flowering phase, less on seed production and much less on seedling establishment and on cloning. Meanwhile and noteworthy, flowering resulted to be the less critical phase for the fulfilment of the species life cycle.Overall, with this perspective article we aim to encourage a constructive debate among the scientific community members and policymakers to set up novel concerted strategies for the conservation of plant species of conservation concern. The challenge of the discussion is the implementation of the current approach with new biological and ecological information to be exclusively targeted at identifying the constraints that limit the generation turnover and furnishing specific indications for active management.

Reproductive biology of Populus deltoides Bartr.

The detailed knowledge on the reproductive biology of plants is required for their successful cultivation and conservation. The reproductive characteristics of trees are required to assess the diversity patterns and community structure of the forests. Understanding the reproductive characteristics, such as, pollination, breeding systems, phenology, and floral biology of Populus deltoides is immensely important; because it is one the most important tree species in India. The review documented the physiological basis of the reproductive characteristics of poplar tree. Literature indicated that the dioecious species shows a regular flowering patternin both the male and female trees, and they produces flower (catkin) every year. In all the species, male flower buds bursted earlier than the vegetative bud, whereas, female flower buds bursted after the emergence of leaves. Unisexual flowering occurs between February and April in both male & female, and the dispersal of seeds reported in late May or early June. Most of the pollen grains exhibited reddish colour. The fruits are capsule shaped, splits into 3or 4 parts, and release cotton like seeds, which are viable for only a short period. Poplar mostly regenerates from seed under natural conditions, but are also capable of asexual or vegetative reproduction under artificial conditions. The male and female plant produces a significant number of hybrids seeds; resulting in an excellent growth of the plants. The species displayed cross-pollination characteristics. The information documented in the current literature will be quite useful to understand the reproductive characteristics of the Populus deltoides.

Effect of elevated temperature on the rate of flowering anthesis and seed set in Olea ferruginea

Plant reproduction and climate are strongly correlated with each other in various aspects, as climate change is the main cause of biotic and abiotic stresses, which adversely affect plant reproductive biology. We conducted a field experiment over two consecutive years to record how warming temperature affects flowering anthesis within inflorescence and the relationship between the flowers with anther dehiscence before anthesis (ADBA) and fruit set with maximum and minimum temperature in Olea ferruginea. The results of linear regression analysis show that there is increase in the rate of ADBA by 0.846 times per unit increase in maximum temperature and 0.789% per unit increase in minimum temperature. Also, there is decrease in fruit set by 0.933% and 0.743% when compared with maximum and minimum temperature respectively. The fruit set was found to be decreased by 0.81% when flowers undergo ADBA. Since the species is self-incompatible, cross pollination and pollen germination becomes impossible after anthesis due to the presence of self-pollen on the stigmatic surface. Our study results suggest that temperature fluctuations could affect rate of anthesis in flowering and reduce seed production under higher temperature. Thus, the impacts of climate extremes on plant life cycles may be as influential as gradual warming. In particular, it appears that throughout the anthropocene, temperature regime fluctuation had a bigger impact on flowering dynamics.

Pollen as the link between floral phenotype and fitness

AbstractPollen plays a key role in plant reproductive biology. Despite the long history of research on pollen and pollination, recent advances in pollen‐tracking methods and statistical approaches to linking plant phenotype, pollination performance, and reproductive fitness yield a steady flow of exciting new insights. In this introduction to the Special Issue “Pollen as the Link Between Phenotype and Fitness,” we start by describing a general conceptual model linking functional classes of floral phenotypic traits to pollination‐related performance metrics and reproductive fitness. We use this model as a framework for synthesizing the relevant literature, highlighting the studies included in the Special Issue, and identifying gaps in our understanding and opportunities for further development of the field. The papers that follow in this Special Issue provide new insights into the relationships between pollen production, presentation, flower morphology, and pollination performance (e.g., pollen deposition onto stigmas), the role of pollinators in pollen transfer, and the consequences of heterospecific pollen deposition. Several of the studies demonstrate exciting experimental and analytical approaches that should pave the way for continued work addressing the intriguing role of pollen in linking plant phenotypes to reproductive fitness.

Re-imagining Reproduction: The Queer Possibilities of Plants.

How did plant sexuality come to so hauntingly resemble human sexual formations? How did plant biology come to theorize plant sexuality with binary formulations of male/female, sex/gender, sperm/egg, active males and passive females-all of which resemble western categories of sex, gender, and sexuality? Tracing the extant language of sex and sexuality in plant reproductive biology, we examine the histories of science to explore how plant reproductive biology emerged historically from formations of colonial racial and sexual politics and how evolutionary biology was premised on the imaginations of racialized heterosexual romance. Drawing on key examples, the paper aims to (un)read plant sexuality and sexual anatomy and bodies to imagine new possibilities for plant sex, sexualities, and their relationalities. In short, plant sex and sexuality are not two different objects of inquiry but are intimately related-it is their inter-relation that is the focus of this essay. One of the key impulses from the humanities that we bring to this essay is a careful consideration of how terms and terminologies are related to each other historically and culturally. In anthropomorphizing plants, if plant sexuality were modeled on human sexual formations, might a re-imagination of plant sexuality open new vistas for the biological sciences? While our definitions of plant sexuality will always be informed by contemporary society and culture, interrogating the histories of our theories and terminologies can help us reimagine a biology that allows for new and more accurate understandings of plants, plant biology, and the evolution of reproduction.

Life-history characteristics and historical factors are important to explain regional variation in reproductive traits and genetic diversity in perennial mosses.

Plants have evolved an unrivalled diversity of reproductive strategies, including variation in the degree of sexual vs. clonal reproduction. This variation has important effects on the dynamics and genetic structure of populations. We examined the association between large-scale variation in reproductive patterns and intraspecific genetic diversity in two moss species where sex is manifested in the dominant haploid generation and sex expression is irregular. We predicted that in regions with more frequent realized sexual reproduction, populations should display less skewed sex ratios, should more often express sex and should have higher genetic diversity than in regions with largely clonal reproduction. We assessed reproductive status and phenotypic sex in the dioicous long-lived Drepanocladus trifarius and D. turgescens, in 248 and 438 samples across two regions in Scandinavia with frequent or rare realized sexual reproduction, respectively. In subsets of the samples, we analysed genetic diversity using nuclear and plastid sequence information and identified sex with a sex-specific molecular marker in non-reproductive samples. Contrary to our predictions, sex ratios did not differ between regions; genetic diversity did not differ in D. trifarius and it was higher in the region with rare sexual reproduction in D. turgescens. Supporting our predictions, relatively more samples expressed sex in D. trifarius in the region with frequent sexual reproduction. Overall, samples were mostly female. The degree of sex expression and genetic diversity differed between sexes. Sex expression levels, regional sex ratios and genetic diversity were not directly associated with the regional frequency of realized sexual reproduction, and relationships and variation patterns differed between species. We conclude that a combination of species-specific life histories, such as longevity, overall degree of successful sexual reproduction and recruitment, and historical factors are important to explain this variation. Our data on haploid-dominated plants significantly complement plant reproductive biology.

Can resin extraction have an effect on the reproductive biology in burseraceae species?: A global analysis

Plant reproductive biology encompasses the study of sexual and asexual reproduction, as well as morphological, physiological, ecological, and genetic aspects influencing these processes. Management can influence reproduction of plants and associated attributes. For economically and culturally important species, it is known that exudates affect biomass of reproductive parts, but limited information is available on how reproductive biology is affected by harvest of exudates. This study reviews the effects of resins extraction in economic and culturally important species of Burseraceae. We conducted a systematic review on studies of floral biology, management, propagation and germination, resource allocation and pollination, hypothesizing that the extraction of exudates negatively impacts the reproductive biology of these plants by altering their mating system, pollination, and reproductive success as a consequence of resource reallocation. We identified that dioecy is the most frequent mating system in Burseraceae plants, and the extraction of exudates negatively affects the reproductive success of the species utilized, since it is related to a decrease in the number of flowers, fruits, and seeds, as well as in the percentage of viability and seed germination. Our review suggests the relevance of conducting studies on the ecophysiological effects of management on resiniferous species. Furthermore, it highlights the difficulty of detecting clear patterns, specific studies should be carried out to corroborate the hypothesis derived from this review. We propose specific strategies that better explore the effect of human management and exudate extraction techniques on vital processes such as germination, development, growth, reproduction, and pollination, in species that are used for this purpose.

Two forty-years for researches on sexual plant reproduction in Wuhan University

<p indent="0mm">Investigations on sexual plant reproduction in Wuhan University was promoted by Prof. Hong-Yuan Yang and Prof. Chang Zhou. After forty-years’ effort remarkable progress has been made in experimental sexual reproductive biology, especially in the field of unfertilized ovule culture and <italic>in vitro</italic> sexual cell manipulation. Their contributions in this field have been summarized in a Prof. Yang-edited book named “forty-year researches on experimental sexual plant reproduction”, which is a remarkable indicator of the transition from traditional descriptive sexual plant reproduction to experimental sexual plant reproduction in China. As a student of Prof. Yang, Prof. Meng-xiang Sun has been also working in this field for forty years and experienced a quick transition from sexual plant reproductive biology to developmental biology of sexual plant reproduction, in which regulatory mechanism of sexual reproduction process is deeply investigated under the guidance of basic theory of developmental biology and based on the combination of molecular and cell biological techniques. After years’ effort they finally catch up with the moving frontier of the field and add new pages in the book of sexual plant reproduction research in Wuhan University. This paper summarizes what they experienced, what they thought and what they did in the two overlapped forty-years respectively, to present some aspects of the researches in Wuhan University.

Phylogenomic loci define the generic boundaries of Gochnatieae and improve resolution at the species level in Moquiniastrum (Compositae)

Understanding the evolution of the tribe Gochnatieae (Compositae) has been the subject of considerable effort in the past decade. This is due to the key position of this tribe in the phylogeny of the sunflower family and the corresponding implications for biogeographic and morphological evolution of Compositae. Previous studies have confirmed the monophyly of this tribe as well as most of the genera that belong to it. However, phylogenetic resolution of Gochnatieae at both the genus- and species-level has remained poor. A subset of new phylogenomic loci used in this study has proven effective and has improved phylogenetic resolution in this group. The results of this work demonstrate Gochnatieae is a well-supported clade comprised of nine genera (Anastraphia, Cnicothamnus, Cyclolepis, Gochnatia, Moquiniastrum, Nahuatlea, Pentaphorus, Richterago, Tehuasca). One recently described genus, Vickia, was not included in this study; but its placement in Gochnatieae as a tenth genus in the tribe is well-justified. The monospecific Cyclolepis, which had been circumscribed within the tribe since its inception but was subsequently removed and designated as incertae sedis since 2014, is also shown to belong to Gochnatieae. We confirmed the monophyletic Moquiniastrum with two well-supported subclades. Ancestral area reconstruction analyses show that Gochnatieae originated in Eastern South America about 53 my. Apparently, except for Cyclolepis and Richterago, the ancestors of the other genera of Gochnatieae originated about 44 my from an area that now corresponds to the central Andes. The presence of the genera in the Chaco phytogeographic province, central Chile, and Mexico-United States-Caribbean is a result of dispersal from the central Andes. The ancestral distribution of Moquiniastrum corresponds to a large area comprising Eastern South America and the current central Andes, about 32 my. Ancestral character state reconstruction that included four characters indicates several states associated with complex plant reproductive biology such as gynodioecy, gynomonoecy, and polygamodioecy are derived in Gochnatieae as are heterogamous capitula (in Moquiniastrum and Richterago), dimorphic and subdimorphic corollas (in Cnicothamnus, Moquiniastrum, and Richterago), and the presence of marginal female corollas (in Moquiniastrum and Richterago). Within Moquiniastrum, two subclades (Densicephalum and Polymorphum) exhibit divergent patterns of trait evolution associated with these reproductive characters which suggests this genus can serve as a model to understand the sexual system evolution in plants.

“Sofiyivka”— a masterpiece landscape design of 18–19 centuries on 225th anniversary of its founding

The material describes the history of the dendrological park "Sofiyivka", as well as its modern material and technical base for scientific research related to monitoring the condition and preservation of flora of the forest-steppe zone of Ukraine; support and development of botanical collections, as well as biotechnology, genetics, breeding and reproductive biology of plants; Landscaping and landscaping not only ensures the preservation of the historic core and the development of the park, but also promotes the creation of already mentioned and other new varieties.

Adaptive and nonadaptive causes of heterogeneity in genetic differentiation across the Mimulus guttatus genome.

Genetic diversity becomes structured among populations over time due to genetic drift and divergent selection. Although population structure is often treated as a uniform underlying factor, recent resequencing studies of wild populations have demonstrated that diversity in many regions of the genome may be structured quite dissimilar to the genome-wide pattern. Here, we explored the adaptive and nonadaptive causes of such genomic heterogeneity using population-level, whole genome resequencing data obtained from annual Mimulus guttatus individuals collected across a rugged environment landscape. We found substantial variation in how genetic differentiation is structured both within and between chromosomes, although, in contrast to other studies, known inversion polymorphisms appear to serve only minor roles in this heterogeneity. In addition, much of the genome can be clustered into eight among-population genetic differentiation patterns, but only two of these clusters are particularly consistent with patterns of isolation by distance. By performing genotype-environment association analysis, we also identified genomic intervals where local adaptation to specific climate factors has accentuated genetic differentiation among populations, and candidate genes in these windows indicate climate adaptation may proceed through changes affecting specialized metabolism, drought resistance, and development. Finally, by integrating our findings with previous studies, we show that multiple aspects of plant reproductive biology may be common targets of balancing selection and that variants historically involved in climate adaptation among populations have probably also fuelled rapid adaptation to microgeographic environmental variation within sites.

Switching it up: algal insights into sexual transitions

While the process of meiosis is highly conserved across eukaryotes, the sexual systems that govern life cycle phase transitions are surprisingly labile. Switches between sexual systems have profound evolutionary and ecological consequences, in particular for plants, but our understanding of the fundamental mechanisms and ultimate causes underlying these transitions is still surprisingly incomplete. We explore here the idea that brown and green algae may be interesting comparative models that can increase our understanding of relevant processes in plant reproductive biology, from evolution of gamete dimorphism, gametogenesis, sex determination and transitions in sex-determining systems.

Diet Drives Differences in Reproductive Synchrony in Two Sympatric Mountain Ungulates in the Himalaya

Ungulates in higher latitudes and altitudes experience sharp seasonal changes in forage abundance and quality. In response, ungulates show varying degrees of synchrony in reproduction. Diet type has been hypothesized to be a determinant of differences in reproductive synchrony. Analyses at global scales using proxies of plant phenology such as climate, latitude and Normalized Difference Vegetation Index (NDVI) have found no evidence in support because such proxies do not capture differences in phenology among plant taxa at local scales. We compared seasonal variations in diet quality with reproductive synchrony in the Himalayan musk deer (Moschus chrysogaster), a browser, and the Himalayan goral (Naemorhedus goral), a grazer, in mid-altitude Himalaya. We also compared seasonal variations in physiological stress using fecal glucocorticoid metabolite (FGM). We identified different stages of female reproductive cycle using fecal concentrations of metabolites of estradiol, pregnanediol-3-glucuronide (PdG) and testosterone and used fecal crude protein (CP) as an indicator of diet quality. In musk deer, fecal estradiol and PdG concentrations showed a dispersed estrous and parturition, respectively. Goral had a more synchronized estrous and parturition. Estrous cycles in both species occurred when diet quality was poor, but parturition occurred when diet quality was high. Greater seasonality in reproduction in goral is driven by sharp phenological changes in graminoids on which it feeds, compared to slow changes in browse on which musk deer feeds. Thus, we show that diet type drives the differences in reproductive synchrony in these two sympatric species. Spring and summer with highest diet quality were times of highest stress in both the ungulates. We hypothesize predation pressure from feral dogs and resource competition with livestock as plausible explanations for this, which need to be tested in future. Our findings also highlight the need for studying relationships among plant phenology, diet type and reproductive biology of ungulates at local scales if we are to understand species responses to global phenomena such as climate change.

PICT: A low‐cost, modular, open‐source camera trap system to study plant–insect interactions

Abstract Commercial camera traps (CTs) commonly used in wildlife studies have several technical limitations that restrict their scope of application. They are not easily customizable, unit prices sharply increase with image quality and importantly, they are not designed to record the activity of ectotherms such as insects. Those developed for the study of plant–insect interactions are yet to be widely adopted as they rely on expensive and heavy equipment. We developed PICT (plant–insect interactions camera trap), an inexpensive (&lt;100 USD) do‐it‐yourself CT system based on a Raspberry Pi Zero computer designed to continuously film animal activity. The system is particularly well suited for the study of pollination, insect behaviour and predator–prey interactions. The focus distance can be manually adjusted to under 5 cm. In low light conditions, a near‐infrared light automatically illuminates the subject. Frame rate, resolution and video compression levels can be set by the user. The system can be remotely controlled using either a smartphone, tablet or laptop via the onboard Wi‐Fi. PICT can record up to 72‐hr day and night videos at &gt;720p resolution with a 110‐Wh power bank (30,000 mAh). Its ultra‐portable (&lt;1 kg) waterproof design and modular architecture is practical in diverse field settings. We provide an illustrated technical guide detailing the steps involved in building and operating a PICT and for video post‐processing. We successfully field‐tested PICT in a Central African rainforest in two contrasting research settings: an insect pollinator survey in the canopy of the African ebony Diospyros crassiflora and the observation of rare pollination events of an epiphytic orchid Cyrtorchis letouzeyi. PICT overcomes many of the limitations commonly associated with CT systems designed to monitor ectotherms. Increased portability and image quality at lower costs allow for large‐scale deployment and the acquisition of novel insights into the reproductive biology of plants and their interactions with difficult to observe animals. ​

Proceedings of the 7th Series of Seminars on Advances in Apomixis Research.

These proceedings contain the abstracts for the presentations given at the 7th biennial Seminars on Advances in Apomixis Research, held virtually on 2–3 and 9 December 2020. The first day hosted the kick-off meeting of the EU-funded Mechanisms of Apomictic Development (MAD) project, while the remaining days were dedicated to oral presentations and in-depth exchanges on the latest progress in the field of apomixis and plant reproductive biology research.

Deep learning-based high-throughput phenotyping can drive future discoveries in plant reproductive biology

Key messageAdvances in deep learning are providing a powerful set of image analysis tools that are readily accessible for high-throughput phenotyping applications in plant reproductive biology.High-throughput phenotyping systems are becoming critical for answering biological questions on a large scale. These systems have historically relied on traditional computer vision techniques. However, neural networks and specifically deep learning are rapidly becoming more powerful and easier to implement. Here, we examine how deep learning can drive phenotyping systems and be used to answer fundamental questions in reproductive biology. We describe previous applications of deep learning in the plant sciences, provide general recommendations for applying these methods to the study of plant reproduction, and present a case study in maize ear phenotyping. Finally, we highlight several examples where deep learning has enabled research that was previously out of reach and discuss the future outlook of these methods.

ConservePlants: An integrated approach to conservation of threatened plants for the 21st Century

Even though plants represent an essential part of our lives offering exploitational, supporting and cultural services, we know very little about the biology of the rarest and most threatened plant species, and even less about their conservation status. Rapid changes in the environment and climate, today more pronounced than ever, affect their fitness and distribution causing rapid species declines, sometimes even before they had been discovered. Despite the high goals set by conservationists to protect native plants from further degradation and extinction, the initiatives for the conservation of threatened species in Europe are scattered and have not yielded the desired results. The main aim of this Action is to improve plant conservation in Europe through the establishment of a network of scientists and other stakeholders who deal with different aspects of plant conservation, from plant taxonomy, ecology, conservation genetics, conservation physiology and reproductive biology to protected area's managers, not forgetting social scientists, who are crucial when dealing with the general public.

The Organization for Tropical Studies: History, accomplishments, future directions in education and research, with an emphasis in the contributions to the study of plant reproductive ecology and genetics in tropical ecosystems

The Organization for Tropical Studies (OTS) has played a pivotal role in our understanding of tropical ecosystems' structure and function. For more than fifty years, OTS has contributed to the training of three generations of tropical biologists and facilitated, supported, and promoted leading-edge research in its field stations. Plant reproductive ecology and genetics have been a significant focus of OTS research since the early 1960s, and Dr. K.S. Bawa made a significant contribution to the advancement of this field. His work improved our understanding of the diversity and evolution of breeding systems in tropical forests, their phenology and pollination ecology, and their mating and genetic structure. We argue that his work inspired other tropical biologists' work and used the work of one of the authors for illustration when appropriate. We point out the need for research in critically important topics to slow down biodiversity loss, prevent the collapse of tropical systems in a changing climate, and the emergence of zoonotic disease. We suggest future research topics for the OTS field stations, including in plant reproductive biology.