Plant Biology最新文献

Hormones have a dominant role in shaping the destiny of plant reproduction. Recent breakthroughs in our understanding of hormone function during floral development have revealed the pivotal roles of cytokinin, gibberellin and auxin. Cytokinin and gibberellin regulate the size and coordination of floral meristems, while auxin and cytokinin take centre stage in initiating and developing organs. In the past decade, remarkable insights have emerged, revealing the dynamic nature of hormonal impacts throughout reproductive development. It has become evident that a complex network, involving multiple plant hormones, orchestrates the success of plant reproduction. Despite substantial cover of certain aspects of plant reproductive development, there remain significant gaps in our understanding of hormonal regulation and the intricate crosstalk between hormones. In this comprehensive review, we delve into current knowledge and address lingering questions regarding hormone-mediated flower development. By arming ourselves with this knowledge, we pave the way for innovative strategies in effective fruit set management and crop improvement.

More than two centuries since the birth of the botanist Matthias Jacob Schleiden, who first described many duckweed (Lemnaceae) species, interest in these small aquatic monocots is still alive. Lemnaceae have high biomass production capacity and can be used as animal feed and in human nutrition. Efficient transformation protocols and available genome data for several Lemnaceae species make them an ideal model system for research into biosynthesis and physiology of sterols and/or steroids in plants, especially monocots. Here we emphasize how studies using duckweed species can address current problems in plant physiology, with a strong focus on sterol and steroid biology in monocots. Further, we discuss how this knowledge can be translated to solve agricultural and industrial problems.

Chitinases are hydrolytic enzymes that catalyse the degradation of chitin, a major component of fungal cell walls and arthropod exoskeletons. Although extensively studied in higher plants, chitinases in pteridophytes remain largely unknown. This review examined the potential of pteridophyte chitinases as a promising resource for advanced biopesticides. Pteridophytes, including ferns and lycophytes, dating back over 450 million years, have evolved unique adaptations to terrestrial environments, suggesting they may possess novel chitinase variants. Research on fern chitinases, particularly in Pteris ryukyuensis and Equisetum arvense, has revealed distinct features, such as LysM domains, which enhance chitin-binding and antifungal activity. PrChi-A chitinase from P. ryukyuensis exhibits remarkable thermal stability and specific binding to chitin oligosaccharides, which could be advantageous for agricultural applications. Additionally, engineered multimeric LysM domains fused with catalytic domains have demonstrated enhanced antifungal effects compared to those of naturally occurring chitinases. These findings highlight the potential of pteridophyte chitinases in developing improved biopesticides against fungal pathogens. The unique evolutionary position of pteridophytes among non-vascular and seed plants suggests they may harbour additional novel chitinase variants with diverse biochemical properties. Further exploration of chitinases across various pteridophyte species could uncover enzymes with enhanced stability, specificity, and efficacy for sustainable agriculture and biotechnology. This review highlights the need for increased research on pteridophyte chitinases to harness their potential as valuable resources for cutting-edge biopesticides and other biotechnological applications.

The hot deserts of the southwestern United States are experiencing increased frequency, severity, and duration of drought due to anthropogenic climate change. Plant communities in these deserts differ in composition, specifically the abundance of annual and perennial species, which could differentiate responses among these ecosystems to drought. Thus, identifying how these desert plant communities respond to prolonged, severe drought is critical to assess vulnerability to climate change. We measured the response of herbaceous plant communities to 4 years of experimentally imposed severe drought in Chihuahuan, Sonoran, and Mojave Desert sites in the southwestern US. We imposed year-round passive rain exclusion treatments with a 66% reduction in ambient rainfall for 4 years at two sites in each of the three US hot deserts. We measured plant species composition and abundance in treatment and control plots during the peak growing season. Vegetative cover increased with seasonal precipitation at all six sites. Species richness and evenness varied in response to drought across all sites over the duration of the experiment. At three of the six sites, species richness increased with seasonal precipitation and at three sites species evenness decreased with seasonal precipitation. In general, we found that community structure was linked to seasonal precipitation more so than cumulative drought in these herbaceous communities of southwestern US deserts, and that these desert communities are highly resilient following prolonged, extreme drought.

The intensification of climate change-induced drought results in unprecedented tree and forest die-offs worldwide, increasingly driven by compound droughts. In this review, we examine the impacts of emerging compound droughts, which involve co-occurring stressors like soil drought and high temperature, along with elevated vapour pressure deficit over prolonged periods and at higher frequency. We explore the physiological and ecological mechanisms underlying tree water and carbon regulation during these extreme conditions, focusing on the balance between water demand and supply, the role of acclimation, and its consequences for ecosystem-level functions. By examining the mechanisms at play from the organ to the ecosystem-scale, we provide a comprehensive understanding of how trees and forests are likely to respond to an increasingly unpredictable climate with a higher likelihood of compound droughts.

Severe droughts affect vegetation through several processes, such as hydraulic failure, early leaf senescence, depletion of carbon reserves, and reduced growth. These, in turn, can delay drought recovery and influence ecosystem functioning beyond the drought duration. The goal of this study is to investigate the direct response and physiological recovery of a Mediterranean oak (Quercus ilex L.) forest in southern France following the 2017 drought. We analysed eddy covariance-based observations of gross primary productivity (GPP), evapotranspiration (ET) and tree sap flow measurements. To study drought recovery, we used a random forest regression model to predict vegetation functioning in the post-drought years based on hydro-meteorological conditions. Potential legacy effects can be indicated by the difference between predicted and actual values. The 2017 drought peaked in autumn, with the lowest soil moisture of the study period 2000-2021. Concurrently, we detected the lowest GPP, ET, and sap flow for this time of the year on record. Despite severe reductions in vegetation functioning during drought, we found no legacy effects on GPP, ET, and sap flow. This suggests that the physiological functioning of Q. ilex woodlands recovers rapidly and completely. We hypothesize that this fast recovery is supported by favourable pre- and post-drought hydro-meteorological conditions, as spring 2017 was unusually sunny but not water-limited, and 2018 was the wettest year in the studied record. High drought resilience of Q. ilex forests is important in the context of anticipated increase in drought frequency and intensity under climate change. However, it remains yet to be determined to what extent the drought resilience can be sustained during potentially recurrent droughts in the future.