Volume 11, Issue 2, April 2019

Increased precipitation prolonged the life cycle of spring and autumn germinated plants, increased dry mass accumulation and seed production, increased the proportion of biomass allocated to stems and leaves and decreased the proportion of reproduction and roots. In the context of climate change, the increase of biomass and seed production in spring and autumn germinated plants enhances the overall competitive advantage of Erodium oxyrhynchum in the plant community, assuming that other species respond less positively than Erodium oxyrhynchum.

The present study was performed on mungbean to determine the effect of treatment with Cd and Fe for 5 and 10 days on redox reactions. The antioxidative enzymes were decreased 10 days after Fe-Cd treatment but were improved by Fe supplementation. A reduction in peroxidase enzymes was observed 10 days after Fe-Cd treatment but levels were improved by Fe treatment. Fe-nutritional status contributed to the mitigation of Cd toxicity even for longer periods of oxidative stress.

Angiosperms invading water from air will have faced problems of carbon supply. How does an amphibious plant grow in both terrestrial and submerged conditions? This manuscript reports on the plasticity of morphological and physiological responses to submergence in an amphibious plant, Hygrophila difformis. This amphibious plant photosynthesizes underwater by utilizing HCO₃⁻ and this ability to utilize HCO₃⁻ is switched on when it is submerged. Ethylene is involved in this submergence acclimation by changing leaf morphology and inducing HCO₃⁻ utilization.

The origin of range-restricted diploid species confined to formerly heavily glaciated areas is little understood. A suitable system to address this question is a group of two autogamous eyebright species, Euphrasia inopinata and E. sinuata, each known only from a few sites in the eastern European Alps. Previous hypotheses suggested these species to be either remnants of the diploid ancestor of the equally autogamous but widespread and polyploid E. minima or as peripheral segregates of a more widespread allogamous diploid species.

This study provides the first complete picture of leaf carbon balance in two economically important genotypes of papaya and demonstrates that neither stomatal effects nor reduced photochemical and carboxylation capacities of the Golden genotype affected CO₂ assimilation through photosynthesis. We consider that physiological processes other than photosynthesis/leaf respiration (LCB) can be as well involved in the worst growth and yield of Golden. For example, higher rates of photorespiration were observed in Sunrise Solo, which could improve the rate of N assimilation into organic compounds, thus contributing to the higher biomass production in Sunrise Solo relative to Golden.

Using newly developed mitochondrial DNA markers we looked at the relationship between three closely related European pine species. We were especially interested in assessing the genetic structure of Pinus uliginosa—a peat bog pine uniquely adapted to the nutrient-sparse bog environment that nowadays is highly endangered due to environmental changes and habitat loss. Surprisingly, we found evidence of strong differentiation between the neighbouring populations of this species and also signatures of hybridization events, shaping its contemporary gene pool. Our results improve current taxonomic knowledge of the studied Pinus mugo complex and could also serve as a basis for the development of successful conservation strategies for peat bog pine.

The goal of the study is to provide an overall perspective on epiphyte–phorophyte networks and their placement with respect to the networks of other more studied biotic interactions. The results showed that epiphyte–phorophyte networks are structured similarly to most other types of networks that involve co-evolutionary interactions as they were, in most cases, significantly nested and modular. It also confirmed that the interaction between vascular epiphytes and host phorophytes is predominantly generalist.

Pre-pollination mechanisms for isolation among sympatric bat-pollinated plants are largely unknown. We investigated the mechanisms for reproductive segregation between four sympatric chiropterophilous bromeliads in Veracruz, Mexico. With ex situ and in situ manual pollination treatments we determined the breeding system by assessing fruiting and seedling success and sampled bat visitors using mist-nets and infrared cameras. Bromeliads showed staggered flowering, different pollen deposition sites on the body of the pollinator and differences in the reward offered. These traits may have evolved to reduce the competitive costs of sharing pollinators while providing a constant supply of food for the nectarivorous bat community.

Tibetan hulless barley is an important economic crop widely grown in highly stressful conditions in the Qinghai-Tibet Plateau and is often challenged by salinity stress. We investigated the temporal metabolic responses to salinity stress by employing the widely targeted metabolomic analysis in leaf samples from two contrasting cultivars. We successfully identified 13 stress-related metabolites representing the core metabolome responsive to salinity stress. Moreover, we revealed that the efficient management of glycolysis and energy consumption, especially during the most stressful time is the key strategy for tolerating salt stress. Finally, some unreported salt-tolerance biomarkers were unveiled in hulless barley.

Much of Australia is covered by an arid zone that has developed over the last 15 million years (Ma). The unique flora that inhabits that arid zone includes plants that have responded differently (expanding or contracting their ranges) to climate and landscape changes. Here we show that one widespread desert grass, Triodia basedowii, has recently (within the last 2 Ma) expanded across the arid zone. Surprisingly, we find evidence of an expansion origin in central or eastern Australia, while the bulk of the diversity in the group to which T. basedowii belongs exists in western Australia.

Variation in gene expression promotes adaptive divergence. In this study, we performed comparative transcriptomics on Melastoma candidum, M. sanguineum and their F₁ hybrid to investigate the role of gene expression in plant species diversification and hybridization. Differentially expressed genes were mostly found between the two parental species, and were related to adaptive traits that limit the species to their habitats. In the F₁ hybrid, although the expression levels of most genes were similar to either parent, a small number of genes had expression levels exceeding both parents, possibly explaining its vigour in certain morphological and adaptive traits.

The multicellular haploid generation of plants (gametophyte) is responsible for sperm and egg production. In the fern Ceratopteris richardii, gametophytes are free-living and may develop into either males or hermaphrodites. This developmental decision is not genetically programmed, but instead is environmentally determined. A pheromone released by hermaphrodites called antheridiogen induces individuals to develop as males. The presence of the bacterium Pseudomonas nitroreducens blocks male induction and results in more individuals developing as hermaphrodites. The bacterium also induces longer but fewer rhizoids to develop in both males and hermaphrodites.

Originally from Europe, Erodium cicutarium (redstem storksbill) spread across both North and South America. The plant grows in diverse habitats from deserts to mountaintops. Has it evolved to grow differently in different habitats during these invasions, and do such differences help it spread? By experimentally growing seeds from many sites in California and Chile, this study discovered strong local genetic differences: plants from dry areas ‘live fast and die young’, flowering weeks earlier than plants from wetter areas. Patterns of local differences among Chilean populations matched those in California, suggesting this species evolves in predictable ways as it spreads.

Seed dispersal is critical to plant fitness and plant community dynamics. However, measuring and tracking all factors that influence seed dispersal effectiveness for any potential seed-disperser relationship would require an unrealistically large amount of time, materials and financial resources. Building on current frameworks, we suggest that seed dispersal ecology quantify seed dispersal at the scale of plant functional groups, in order to reduce complexity to manageable levels. Based on functional group classifications, plant species can be distinguished by their level of dependence on seed dispersal and its mechanisms.

The dynamics in the seedling community in the forest understory play a central role in directing plant recruitment and the future composition and structure of the forest. In tropical forests large mammals have an important role as seed dispersers, but many of these mammals are threatened by human activities, including hunting. This experimental study in Nigerian rainforests reveals that hunting indirectly reverses the importance of inter-seedling competition and dispersal limitation. Thus, the loss of large mammals, such as apes and monkeys, is likely to change the future of the forests.