Plant Reproduction Research Articles

Genome-wide analysis and characterization of TPD1 family proteins in pearl millet (Cenchrus americanus): Insights into reproductive regulation and phytohormone responses.

The Tapetum Determinant 1 (TPD1) family proteins are known to play a crucial role in the regulation of reproduction in plants, including Cenchrus americanus (pearl millet). However, members of TPD1 family proteins have not been fully identified. The current study aims to identify and characterize the TPD1 family proteins in Cenchrus americanus (L.) Morrone. Seven transmembrane proteins (from 127 to 172 aa) comprising TPD1 domain were identified via genome-wide mining. Analysis of gene expression during developmental stages revealed high expression of four CaTPD1s in reproductive organs. Treatment with phytohormones showed that the expression of CaTPD1s was repressed by hormone treatments except CaTPD1_Ch4.1 and CaTPD1_Ch4.3 which are highly expressed in response to brassinolide and auxin, respectively. Screening of cis-elements in the promoter of CaTPD1s revealed various cis-elements related to phytohormone regulation, wound response, abiotic stress defense, and light response. The phylogenetic tree revealed distinct clustering of CaTPD1_Ch6 and CaTPD1_Ch5 among the other CaTPD1s, which revealed close relationships with the orthologs from Arabidopsis and rice that are known to have a critical role in tapetum development and pollen and ovule production. Hence, this study affirms the role of the CaTPD1s genes in the growth and reproduction during pearl millet developmental stages.

Female-biased nectar production is associated with the Darwin's inflorescence syndrome.

Plant reproduction is influenced not only by individual flower characteristics but also by the arrangement of flowers within inflorescences. In bee-pollinated plants with protandrous flowers in vertical acropetal inflorescences - where male fertile flower structures mature before female ones and basal flowers open first (i.e., Darwin's inflorescence configuration) - male-phase flowers are positioned above female-phase flowers. This arrangement benefits from the upward foraging motion of bees, reducing pollen transfer between flowers of the same plant and increasing pollen export. Additionally, female-biased nectar production in these species could reinforce upward bee movement, further reducing self-pollen transfer. We conducted a comparative study of 112 hermaphrodite angiosperm species with temporal separation of male and female reproductive functions (i.e., dichogamy) to explore whether female-biased nectar production is common among bee-pollinated species with Darwin's inflorescence configuration. Our results revealed female-biased nectar production in bee-pollinated species with Darwin's inflorescence configuration. In the absence of bee pollination, species with this type of inflorescence exhibit male-biased nectar production. Gender-biased nectar production is absent in species lacking this inflorescence type. Female-biased nectar production in vertical acropetal inflorescences with protandrous flowers likely evolved independently in different bee-pollinated species to enhance pollen export. Our study emphasizes the need for microevolutionary research on how nectar production patterns adapt to bee pollination in species with Darwin's inflorescence configuration.It also calls for investigation into the developmental biases influencing nectar production in plants with dichogamous flowers.

Impact of Seasonal Atmospheric Factors and Photoperiod on Floral Biology, Plant-Pollinator Interactions, and Plant Reproduction on Turnera ulmifolia L. (Passifloraceae).

Reproductive traits and plant-pollinator interactions largely depend on seasonal weather conditions, which are species-specific. Turnera ulmifolia is an ornamental plant distributed worldwide. There is little information about plant species' reproductive ecology and environmental factors' impact on it. Here, we aimed to examine the effects of seasonal atmospheric factors (e.g., temperature, light, relative humidity, rainfall) and photoperiod on flowering, interactions with flower visitors, and the reproductive success of Turnera ulmifolia in West Bengal, India. Flowering intensity peaked in hot summers and dropped in cold winters, correlating positively with temperature and humidity. Flower opening and closing occurred earlier on hot days, while flower longevity increased in winter, showing a negative correlation with temperature and humidity. Pollen and ovule production were lower in cold weather, positively linked to temperature and humidity. The self-compatible plant was moderately dependent on pollinators and had no pollination deficit in open conditions. Visitor abundance, richness, and diversity varied season-wise, with higher values during spring-summer. Based on pollinating agents, the plant showed multiple pollination modes (e.g., melittophily, myophily, myrmecophily, and psychophily). Effective pollinators were Amegilla zonata, Borbo cinnara, Halictus acrocephalus, Nomia (Curvinomia) strigata, and Tetragonula iridipennis. The fruit set (%) did not differ significantly season-wise, but the seed set remained higher in the hot days of summer than in cold winter. Therefore, it can be concluded that atmospheric factors and photoperiod significantly impact floral traits, plant-pollinator interactions, and plant reproduction.

The PEBP genes FLOWERING LOCUS T and TERMINAL FLOWER 1 modulate seed dormancy and size.

The phosphatidylethanolamine-binding protein (PEBP) family members FLOWERING LOCUS T (FT) and TERMINAL FLOWER1 (TFL1) are major regulators of plant reproduction. In Arabidopsis, the FT/TFL1 balance defines the timing of floral transition and the determination of inflorescence meristem identity. However, emerging studies have elucidated a plethora of previously unknown functions for these genes in various physiological processes. Here, we characterized potential roles in seed size and dormancy of FT and TFL1 in Arabidopsis thaliana using CRISPR mutants and reporter analysis. Our findings unveiled a role for TFL1 in seed dormancy while confirming the role of FT in regulating this trait. We showed that the interplay between these two genes in seed dormancy is antagonistic, mirroring their roles in flowering time and inflorescence architecture. Analysis of reporter lines demonstrated that FT and TFL1 are partly co-expressed in seeds. Finally, we showed that total seed yield is affected in these mutants. Together, our results highlight the versatility of these two genes beyond their canonical functions. The impact of FT and TFL1 on seed characteristics emphasizes the significance of approaching gene studies from various perspectives, enabling the identification of multifaceted molecular factors that could play a major role in shaping the future of agriculture.

Floral Regulation: The Significant Virtue of Horticultural Flowering Plants

Flowering is a complex developmental mechanism and is essential for successful reproduction in plants. Complex regulatory networks transform vegetative shoot apical meristems into inflorescence meristems. Further, floral meristems transition to floral bud outgrowth and flowering. Floral regulatory pathways are independently involved in flowering, and most of what we know about genetic regulation comes from model plants. Despite the advancements in plant development biology, the understanding of molecular mechanisms and floral signals in horticultural plants is complex. Studies on gene regulatory mechanisms provide a global view of flowering in horticultural plants. In this paper, we discuss the flowering pathways converging on complex gene regulatory mechanisms and summarize the recent findings in horticultural plants in order to help us understand how they regulate flowering and provide an update for future research.

Interview with Associate Editor Charlotte Kirchhelle

ABSTRACT Charlotte Kirchhelle is Chargée de Recherche at the Laboratory for Plant Reproduction and Development in the National Institute for Agriculture, Food and Environment Research (INRAE) at École normale supérieure (ENS) de Lyon in Lyon, France. After earning her undergraduate and master's degrees in plant genetics at the Technical University of Munich in Germany, Charlotte moved to the UK for her PhD at the University of Oxford. Supervised by Dr Ian Moore, her doctoral work uncovered a novel endomembrane trafficking pathway that controls cell edge-based growth in Arabidopsis thaliana. After a short postdoc, she started her own lab at Oxford and subsequently moved to ENS de Lyon in 2021, where her team continues to investigate the role of the cell edge in plant signalling, mechanotransduction and morphogenesis. Charlotte joins Journal of Cell Science as an Associate Editor in 2025, bringing to JCS her expertise in mechanobiology and computational modelling for plant model systems as well as a passion for asking fundamental questions about cell and developmental biology. We spoke with Charlotte over Zoom about her career, advice for young scientists, and her mission to encourage plant scientists to ‘branch out’ into the biological community.

Revisiting the female germline cell development.

The formation of the female germline is the fundamental process in most flowering plants' sexual reproduction. In Arabidopsis, only one somatic cell obtains the female germline fate, and this process is regulated by different pathways. Megaspore mother cell (MMC) is the first female germline, and understanding MMC development is essential for comprehending the complex mechanisms of plant reproduction processes. Recently, more advanced technologies such as whole-mount single-molecule fluorescence in situ hybridization (smFISH), laser-assisted microdissection (LCM), chromatin immunoprecipitation/sequencing, and CRISPR gene editing have provided opportunities to reveal the mechanism of female germline development at different stages. Single-cell transcriptome/spatial transcriptomics analysis helps to investigate complex cellular systems at the single-cell level, reflecting the biological complexity of different cell types. In this review, we highlight recent progress that facilitates the development of the female germline to explore the roles of crucial gene regulatory networks, epigenetic pathways, cell-cycle regulators, and phytohormones in this process. This review discusses three key phases in female germline development and provides the possibility of distinct pathways restricting germline development in the future.

Response of the germinable soil seed bank of temperate Leymus chinensis meadows to mowing regimes.

Mowing is a primary practice in temperate L. chinensis meadows, which are severely degraded due to frequent mowing, overgrazing, and other factors, necessitating restoration and sustainable management. The natural recovery of these grasslands hinges on their germinable soil seed banks, which form the basis for future productivity. Thus, germinable soil seed banks are critical for restoring overexploited meadows. In this study, we conducted germination experiments on 135 soil samples from various depths to comprehensively analyze the germinable seed bank under different mowing regimes. The main results were as follows: (1) the germinable soil seed bank density decreased significantly with a mowing event per year (C1), and the number of perennial grass seeds and upper grass seeds also decreased under the mowing event per year; (2) the size of the germinable soil seed bank increased under the other mowing regimes (control area without mowing or grazing, CK; mowing event every 2 years, C2; mowing event every 3 years, C3; and mowing event every six years, C6) relative to that under once-a-year mowing. With increasing soil depth, the number of germinable soil seeds decreased significantly. Most of the seeds in the germinable soil seed banks were distributed in the 0-2 cm soil layer, accounting for approximately 80% of the total, and at depths of 5-10 cm, the number of seeds of upper grasses was greater than that of perennial grasses. (3). During the mowing event each year, the seed bank of germinable soil seeds significantly decreased. Mowing every 2 years provides a one-year interval for natural vegetation growth, allowing for greater retention of seeds in the germinable soil seed bank. Mowing every 6 years significantly reduces the disturbance frequency, providing ample time for plant reproduction and resulting in the accumulation of germinable seeds in the soil.

Titanium dioxide -mediated regulation of enzymatic and non-enzymatic antioxidants, pigments, and diosgenin content promotes cold stress tolerance in Trigonella foenum-graecum L.

Abiotic stresses, notably cold stress, significantly influence various aspects of plant development and reproduction. Various approaches have been proposed to counteract the adverse impacts of cold stress on plant productivity. The unique properties of nanoparticles contribute to an enhanced tolerance of plants to challenging conditions. This study explores the impact of titanium dioxide nanoparticles (TiO2 NPs) on cold-stress tolerance in fenugreek, as well as genes expression involved in the diosgenin biosynthesis pathway. Varied concentrations of TiO2 NPs (0, 2, 5, and 10 ppm) were sprayed on fenugreek plants subjected to cold stress at 10 °C during 6, 24, and 48 h. Our findings revealed that the utilization of 2 and 5 ppm of TiO2 NPs, positively influenced pigments biosynthesis and enzymatic and non-enzymatic antioxidant activities. It also effectively reduced electrolyte leakage and malondialdehyde content, mitigating the adverse effects of cold stress. The study also highlighted TiO2 NPs’ affirmative impact on defense signaling pathways, including abscisic acid, nitric oxide, and auxin, in fenugreek. Moreover, TiO2 NPs significantly influenced the expression of genes related to diosgenin biosynthesis. Simultaneous exposure to cold stress and TiO2 NPs led to a substantial increase in diosgenin content, with the upregulation of SEP, SQS, CAS, and SSR genes compared to control conditions. This research indicated that TiO2 NPs application could effectively stimulate fenugreek biosynthesis of primary and secondary metabolites, consequently enhancing plant tolerance to cold stress. The study’s outcomes hold promise for potential applications in the metabolic engineering of diosgenin in fenugreek.

Domestikasi Tumbuhan Bemban (Donax Canniformis) Untuk Keberlanjutan Usaha Kerajinan Bili Di Desa Lampanah Tunong, Aceh Besar

The bemban plant (Donax canniformis) has important meaning for the community in Lampanah Tunong Village, Indrapuri District, Aceh Besar Regency. Together with 4 (four) other villages around it, this village has become a center for woven bemban crafts with production products that are typical superior products for Aceh Besar Regency. Apart from supporting the development of the tourism sector and creative industry, this woven bemban craft product has been able to improve the economy and welfare of the local community. The lack of implementation of the concept of sustainable development (sustainable development) has resulted in vulnerability to the continuity of this highly prospective business. The provision of raw materials that completely relies on availability in nature has resulted in the increasingly extinct population of burden plants. The rate of handicraft production which is not commensurate with the ability of natural plant reproduction has caused the community to have to bring in raw materials from outside the village. This of course has an impact on increasing production costs and reducing opportunities for profits. Without systematic and strategic efforts, it is feared that availability from outside the village will also threaten its sustainability. To overcome this, the Service Team offers a concrete solution in the form of domestication efforts by transforming wild bemban plants into cultivated bemban plants through the introduction of cultivation techniques, nurseries and cultivation demonstration plots as well as improving and developing marketing techniques through product diversification and the use of digital marketing. The methods used include: counseling/tutorials and direct practice in the field with stages consisting of: preparation, coordination, implementation, coaching, and trials/evaluation. Through this service activity, it is hoped that the sustainability of the bemban woven craft business will be realized (SDGs 11), increase economic growth (SDGs 8), reduce poverty (SDGs 1) and improve the welfare (SDGs 3) of the community, especially partner craftsmen (SDGs 17).

Non-adapted bacterial infection suppresses plant reproduction.

Environmental stressors, including pathogens, substantially affect the growth of host plants. However, how non-adapted bacteria influence nonhost plants has not been reported. Here, we reveal that infection of Arabidopsis flowers by Xanthomonas oryzae pv. oryzae PXO99A, a bacterial pathogen causing rice blight disease, suppresses ovule initiation and reduces seed number without causing visible disease symptoms. TleB, secreted by the type VI secretion system (T6SS), interacts with plant E3 ligase PUB14 and disrupts the function of the PUB14-BZR1 module, leading to decreased ovule initiation and seed yield. On the other site, PUB14 concurrently promotes TleB's degradation. Our findings indicate that bacterial infections in nonhost plants directly repress offspring production. The regulatory mechanism by effectors PUB14-BZR1 is widely present, suggesting that plants may balance reproduction and defense and produce fewer offspring to conserve resources, thus enabling them to remain in a standby mode prepared for enhanced resistance.

The RAD6-like Ubiquitin Conjugase Gene OsUBC7 Has a Positive Role in the Early Cold Stress Tolerance Response of Rice.

Cold stress poses a significant threat to Asian rice cultivation, disrupting important physiological processes crucial for seedling establishment and overall plant growth. It is, thus, crucial to elucidate genetic pathways involved in cold stress tolerance response mechanisms. We mapped OsUBC7, a Radiation-sensitive 6 (RAD6)-type homolog of rice, to a low-temperature seedling survivability (LTSS) QTL and used genomics, molecular genetics, and physiological assays to assess its role in plant resilience against low-temperature stress. OsUBC7 is cold responsive and has higher expression levels in cold-tolerant japonica than cold-sensitive indica. Overexpression of OsUBC7 enhances LTSS of indica and freezing tolerance of Arabidopsis, increases levels of soluble sugars and chlorophyll A, boosts leaf development after cold exposure, and increases leaf cell numbers and plants size, but it does not affect membrane stability after cold stress exposure. Additionally, OsUBC7 has a positive role for germinability in the presence of salt and for flowering and yield-related traits. The OsUBC7 protein physically interacts with the developmental stage-specific and histone-modifying E3 ligases OsRFPH2-12 and OsHUB1/2, respectively, and potential target genes such as cell cycle dependent kinases were identified. OsUBC7 might contribute to cold resilience by regulating sugar metabolism to provide energy for promoting cellular homeostasis restoration after cold stress exposure via new cell growth, particularly in leaf cells crucial for photosynthesis and metabolic activity, possibly by interacting with cell cycle regulating proteins. Overall, the present study suggests that OsUBC7 may be involved in plant development, reproduction, and stress adaptation, and contributes to a deeper understanding of rice plant cold stress tolerance response mechanisms. OsUBC7 may be a promising candidate for improving crop productivity and resilience to stressful environments.

Circadian- and Light-Driven Rhythmicity of Interconnected Gene Networks in Olive Tree.

A circadian clock (CC) has evolved in plants that synchronizes their growth and development with daily and seasonal cycles. A properly functioning circadian clock contributes to increasing plant growth, reproduction, and competitiveness. In plants, continuous light treatment has been a successful approach for obtaining novel knowledge about the circadian clock. The olive tree (Olea europaea L.) is one of the most important crops in the Mediterranean area, and, so far, limited information is available on its CC gene network. Here, we studied the behavior of circadian rhythm genes under LD (light/darkness) and LL (light/light) conditions, the relationships in this network, and the ability of the treatments to modulate gene expression in the photoprotective pigment and lipid biosynthesis pathways. One month of LL conditions increased olive growth performance, but LL exposure also caused reductions in vegetative growth and chlorophyll accumulation. A panel was designed for a study of the transcription expression levels of the genes involved in light perception, the CC, and secondary metabolite and fatty acid biosynthesis. Our results revealed that the levels of 78% of the transcripts exhibited intraday differences under LD conditions, and most of them retained this rhythmicity after exposure to one and two months of LL conditions. Furthermore, co-regulation within a complex network among genes of photoreceptors, anthocyanidins, and fatty acids biosynthesis was orchestrated by the transcription factor HY5. This research enriches our knowledge on olive trees grown under prolonged irradiation, which may be attractive for the scientific community involved in breeding programs for the improvement of this species.

Invariant Spatial Pattern Across Mediterranean Scrublands in the Iberian Pear (Pyrus bourgaeana).

The spatial distribution pattern of plant species is frequently driven by a combination of biotic and abiotic factors that jointly influence the arrival, establishment, and reproduction of plants. Comparing the spatial distribution of a target plant species in different populations represents a robust approach to identify the underlying mechanisms. We mapped all reproductive individuals of the Iberian pear (Pyrus bourgaeana) in five plots (1.39-8.57 km2) differing in the activity of seed dispersers and vertebrate herbivores in southern Iberian Peninsula. We used Thomas point process models to quantify the consistency in the spatial pattern and the level of spatial aggregation of this mammal-dispersed tree among the five populations. We tested two hypotheses: (i) because the clumped defecation behavior of some dispersers can lead to local tree aggregation, and because denser groups of fruiting trees can limit seed dispersal by attracting frugivores to specific sites, we expected a consistent small-scale aggregation pattern across all populations; and (ii) because ungulates reduce recruitment by preying on seeds and seedlings, we hypothesize that ungulate activity will show negative relationships with tree density and level of aggregation. Our spatial analysis revealed consistent and highly aggregated small-scale patterns of all Iberian pear populations, with one critical scale aggregation, a low density of clusters and high variability in the number of trees per cluster. Ungulate activity and the number of trees per cluster showed a marginally significant negative correlation, suggesting that in areas with higher ungulate activity, trees tend to form less dense clusters. Although several of the underlying processes varied greatly among the five study sites, the Iberian pear showed a relatively consistent spatial pattern with just quantitative nuances throughout the entire region. This result has significant implications for the reproductive success of the species, management strategies, and ultimately the long-term persistence of populations.

Boron controls apical dominance in Pea (Pisum sativum) via promoting polar auxin transport.

Plant architecture and subsequent productivity are determined by the shoot apical dominance, which is disturbed by the deficiency of boron, one of the essential trace elements for plant growth and reproduction. However, the mechanism by which B controls shoot apical dominance or axillary bud outgrows under B deficiency is still unclear. This work aimed to investigate the mechanistic basis of this process, with focus on the interaction between B and polar auxin transport. Adopting an all-buds phenotyping methodology and employing several complementary approaches, we found that boron deficiency inhibited plant growth and changed the shoot architecture, resulting in the outgrowth of axillary buds at nodes 1-3. This was related to the auxin accumulation in shoot apical parts buds under B deficiency. Applying N-1-naphthylphthalamic acid to inhibit auxin transport from the shoot apex promoted the outgrowth of axillary buds in boron-sufficient (+B) plants. In decapitated plants, the application of exogenous auxin to the shoot apex only inhibited the outgrowth of axillary buds in +B plants. At higher auxin doses, the toxic effect of IAA was observed in the lower part of the shoot, which was more severe in +B plants than in B-deprived (-B) plants. Furthermore, the expression of PsPIN3 was significantly downregulated under -B conditions. These results indicate that B deficiency inhibits PAT from the apical bud through the main stem to the lower parts, leading to an increase of auxin level in the apical bud, which inhibits the growth of apical buds while stimulating the outgrowth of axillary buds.

Nectar-Feeding Behavior in the Mallee Ringneck, Barnardius zonarius barnardi.

Opportunistic nectarivory occurs in many avian lineages around the world. In order to understand the implications of this behavior to plant reproduction via pollination and to other nectarivores via competition, more thorough descriptions of opportunistic nectar-feeding behavior are necessary. We observed nectar feeding of the mallee ringneck, Barnardius zonarius barnardi, on flowers of the spotted emu bush, Eremophila maculata, in the temperate mallee of South Australia. Here, we describe the nectar-feeding behavior of B. zonarius barnardi and discuss the implications for competition with honeyeaters and the reproduction of E. maculata. We also compare the morphology of the feeding apparatus of B. zonarius barnardi with that of nectarivorous parrots, lorikeets and lories, to determine whether they share convergent morphological features to facilitate the consumption of nectar. Finally, we suggest avenues for future natural history work to better document opportunistic avian nectarivory in Australian ecosystems.

Deciphering the Vulnerability of Pollen to Heat Stress for Securing Crop Yields in a Warming Climate.

Climate change is leading to more frequent and severe extreme temperature events, negatively impacting agricultural productivity and threatening global food security. Plant reproduction, the process fundamental to crop yield, is highly susceptible to heatwaves, which disrupt pollen development and ultimately affect seed-set and crop yields. Recent research has increasingly focused on understanding how pollen grains from various crops react to heat stress at the molecular and cellular levels. This surge in interest over the last decade has been driven by advances in genomic technologies, such as single-cell RNA sequencing, which holds significant potential for revealing the underlying regulatory reprogramming triggered by heat stress throughout the various stages of pollen development. This review focuses on how heat stress affects gene regulatory networks, including the heat stress response, the unfolded protein response, and autophagy, and discusses the impact of these changes on various stages of pollen development. It highlights the potential of pollen selection as a key strategy for improving heat tolerance in crops by leveraging the genetic variability among pollen grains. Additionally, genome-wide association studies and population screenings have shed light on the genetic underpinnings of traits in major crops that respond to high temperatures during male reproductive stages. Gene-editing tools like CRISPR/Cas systems could facilitate precise genetic modifications to boost pollen heat resilience. The information covered in this review is valuable for selecting traits and employing molecular genetic approaches to develop heat-tolerant genotypes.

Knowledge Gaps on the Effectiveness of Seed Dispersal by Mammals and the Effect of Human Disturbances: A Review

Seed dispersal by frugivorous mammals is crucial for plant reproduction, but anthropogenic disturbances can disrupt this process. However, there is a lack of research on mammalian seed dispersal in anthropogenic habitats, with few systematic literature reviews available. In order to address this gap, a review of scientific literature published since 1990 was conducted. A total of 275 articles from 52 countries, predominantly from South America, were found for the review. These articles contained information on 764 mammal species from 54 families, with Canidae being the most studied. The studies focused on various aspects of seed dispersal, including animal visitation rates (60%), seed quantity in faeces (78.9%), seed viability (49.1%), germination (49.5%), and seedling recruitment. However, only a small percentage of the studies examined the impacts of human disturbance on seed dispersal (5.8%), particularly the quantity of seeds dispersed. There is a need for further studies that integrate the analysis of seed dispersal effectiveness by mammals while considering the effects of human disturbances, particularly in areas with high plant and mammal diversity threatened by human activities.

Effects of Biological Factors and Temperature Elevation on Stigmatic Receptivity and Pollen Tube Growth in Diploid and Hexaploid Plum Genotypes [Prunus salicina and Prunus insititia

ABSTRACTPremise of the study. Biological factors and environmental stresses are predominant elements affecting the progamic phase of sexual plant reproduction. Thus, new knowledge is needed to select and develop cultivars adapted to these changes. This work was conducted to evaluate the pollen growth dynamics and the stigmatic receptivity at normal and elevated temperatures, in 12 Tunisian plum genotypes selected based on six different biological factors. Methods. The pistils were hand‐pollinated using their own pollen, and then the dynamics of pollen tube growth and stigma receptivity of Tunisian plum genotypes were surveyed under ambient temperature and under 35 °C. Key results. Results showed that the differences in flower size, geographical origin and drought tolerance did neither affect pollen growth dynamics nor stigma receptivity. However, the polyploidization enlarged the stigmatic receptivity but does not affect the pollen dynamics. Flowering time and wild plantation fasten the pollen growth and enlarge the stigmatic receptivity. We assume that, in particular case, the flowering plants seem to opt for an enlarged stigmatic receptivity and a rapid pollen growth as reproductive strategies to ‘hold on for dear life’. Experiments conducted at 35 °C showed that the temperature elevation accelerates pollen growth dynamics, while it shortens the stigmatic receptivity period. In particular, two accessions: the wild plum ‘Sauvage’ and the late flowering ‘Tasstour Hamra Tardive’ showed faster pollen growth and enlarged stigmatic receptivity, compared to other accessions. Conclusion. The main relevant conclusion of this work resides in the identification of the best adapted Tunisian genotypes that could be selected as pollen sources to extend the pollination period. Especially, accessions presenting a tolerance to high‐temperature deserve serious attention.

Wild Bee Diversity and Bee-Plant Interactions in Tropical and Temperate Forest Clearings in a Natural Protected Area in Central West Mexico.

Bees rely on plants for nutrition and reproduction, making the preservation of natural areas crucial as pollinator reservoirs. Seasonal tropical dry forests are among the richest habitats for bees, but only 27% of their original extent remains in Mexico. In contrast, temperate forests harbor fewer bee species and face high deforestation rates, with 40% of their area converted to other land uses. This study aimed to estimate the α and β diversities of wild bees and compare bee-plant interaction networks between these two vegetation types. Wild bees and their interactions with plants were monitored for one year in four sites within the Área de Protección de Flora y Fauna Sierra de Quila. Two sites corresponded to seasonal tropical dry forest and two to temperate forest. α and β diversity, connectance, nestedness, web asymmetry, and niche overlap were analyzed. Sierra de Quila harbors high bee diversity, with 155 species in tropical dry forest and 103 in temperate forest. Species turnover between vegetation types was high, although nine species used floral resources in both forests, connecting the interaction networks. Sierra de Quila diverse habitats promote high bee diversity, with niche partitioning and low connectance facilitating coexistence across different vegetation types.