Hong Kong Biotechnology Organization

Leaf intrinsic water use efficiency (iWUE) quantifies the trade-off between carbon assimilation and water loss in plants, and is constrained by leaf traits such as maximum carboxylation capacity (Vc,max) and stomatal conductance. Yet, the potential links of iWUE with leaf elementomes across different forest types remain unclear. Here, we analyzed iWUE (estimated by leaf carbon isotopes) variability and its associations with Vc,max, stomatal conductance (estimated by 18O enrichment in leaf dry matter above source water, Δ18O), and leaf elementomes across 82 tree species from temperate, subtropical and tropical forests, and evaluated the effectiveness of leaf reflectance spectroscopy as an indicator of iWUE variability and trait-iWUE associations. Across species, Vc,max, Δ18O, leaf mass per area (LMA) and leaf iron, nitrogen, sodium and manganese concentrations were the traits most strongly associated with cross-site iWUE variability. Furthermore, climatic factors (mean annual precipitation, mean annual temperature and climate moisture index) shaped trait-iWUE covariation by negatively linking leaf elements and positively with LMA, which affected iWUE more directly than indirectly via Vc,max and Δ18O. Leaf reflectance spectroscopy accurately predicted iWUE (R2 = 0.83), and the trait-iWUE relationships derived from spectral modelling were consistent with those obtained through field measurements. These findings reveal strong linkages between the leaf elementomes and iWUE, and highlight the potential of reflectance spectroscopy for characterizing iWUE variability and trait-iWUE relationships, thereby improving process modelling of forest carbon and water cycles.

<strong class="journal-contentHeaderColor">Abstract.</strong> Accurate assessment of leaf functional traits is crucial for a diverse range of applications from crop phenotyping to parameterizing global climate models. Leaf reflectance spectroscopy offers a promising avenue to advance ecological and of robust hyperspectral models for predicting leaf photosynthetic capacity and associated traits from reflectance data has been hindered by limited data availability across species and environments. Here we introduce the Global Spectra-Trait Initiative (GSTI), a collaborative repository of paired leaf hyperspectral and gas exchange measurements from diverse ecosystems. The GSTI repository currently encompasses over 7500 observations from 397 species and 41 sites gathered from 36 published and unpublished studies, thereby offering a key resource for developing and validating hyperspectral models of leaf photosynthetic agricultural research by complementing traditional, time-consuming gas exchange measurements. However, the development capacity. The GSTI database is developed on GitHub (<a href="https://github.com/plantphys/gsti" target="_blank" rel="noopener">https://github.com/plantphys/gsti</a>) and published to ESS-dive <a href="https://data.ess-dive.lbl.gov/datasets/doi:10.15485/2530733" target="_blank" rel="noopener">https://data.ess-dive.lbl.gov/datasets/doi:10.15485/2530733</a>, Lamour et al., 2025). It includes gas exchange data, derived photosynthetic parameters, and key leaf traits often associated with traditional gas exchange measurements such as leaf mass per area and leaf elemental composition. By providing a standardized repository for data sharing and analysis, we present a critical step towards creating hyperspectral models for predicting photosynthetic traits and associated leaf traits for terrestrial plants.

Primordial follicles are the starting point of follicular development and the basic functional unit of female reproduction. Primordial follicles are formed around birth, and most of the primordial follicles then enter a dormant state. Since primordial follicles are limited in number and can’t be renewed, dormant primordial follicles cannot be reversed once they enter the growing state. Thus, the orderly occurrence of primordial follicles selective activation directly affects the rate of follicle consumption and thus determines the length of female reproductive lifespan. Studies have found that appropriately inhibiting the activation rate of primordial follicles can effectively slow down the rate of follicle consumption, maintain fertility and delay ovarian aging. Based on the known mechanisms of primordial follicle activation, primordial follicle in vitro activation (IVA) technique has been clinically developed. IVA can help patients with premature ovarian failure, middle-aged infertile women, or infertile women due to gynecological surgery treatment to solve infertility problems. The study of the mechanism of selective activation of primordial follicles can contribute to the development of more efficient and safe IVA techniques. In this paper, recent mechanisms of primordial follicle activation and its clinical application are reviewed.

Abstract Saline‐alkali stress is one of the major abiotic stresses that severely affect rice yield. However, the mechanism by which saline‐alkali stress regulates grain filling in rice is still unclear. In this study, Oryza sativa L. spp. Indica cultivar Chaoyou1000 (C1000) was exposed to post‐anthesis saline‐alkali conditions at 6 days after anthesis, which significantly reduced the grain weight by suppressing the accumulation of starch and non‐structural carbohydrates in grains. Further analysis found that 1‐aminocyclopropane‐1‐carboxylate (ACC), a precursor for ethylene, was increased by saline‐alkali treatment. qRT‐PCR results showed that several key genes involved in ethylene biosynthesis, including the OsACS and OsACO genes, were upregulated in saline‐alkali‐treated grains. In addition, genes involved in the ethylene signalling pathway were also induced by saline‐alkali stress. Exogenous ethylene application reduced grain weight and both starch and NSC contents in grains of C1000, suggesting that saline‐alkali‐induced ethylene has a negative effect on grain filling. Furthermore, the gene expression levels of OsSUS, OsAGPL, OsAGPS, OsSSI and OsSSIIIa, which are key genes in the starch biosynthesis pathway, were downregulated in saline‐alkali‐treated grains. In agreement, assays on these enzymes further revealed that saline‐alkali stress decreased the activities of sucrose synthase (SUS), adenosine diphosphate glucose pyrophosphorylase (AGP) and starch synthase (StS). Together, our results indicated that saline‐alkali stress suppressed the enzyme activities involved in the conversion of sucrose to starch by elevating ethylene production, which led to inhibition of grain filling.

In the face of global food security crises, it is necessary to boost agricultural production. One factor hampering the attempts to increase food production is elevated soil salinity, which can be due to salt that is naturally present in the soil or a consequence of excessive or prolonged irrigation or application of fertiliser. In response to environmental stresses, plants activate multiple molecular mechanisms, including the timely activation of stress-responsive transcriptional networks. However, in the case of salt stress, the combined effects of the initial osmotic shock and the subsequent ion-specific stress increase the complexity in the selective regulation of gene expressions involved in restoring or maintaining osmotic balance, ion homeostasis and reactive oxygen species scavenging. Histone modifications and chromatin remodelling are important epigenetic processes that regulate gene expressions by modifying the chromatin status and recruiting transcription regulators. In this review, we have specifically summarised the currently available knowledge on histone modifications and chromatin remodelling in relation to plant responses to salt stress. Current findings have revealed the functional importance of chromatin modifiers in regulating salt tolerance and identified the effector genes affected by epigenetic modifications, although counteraction between modifiers within the same family may occur. Emerging evidence has also illustrated the crosstalk between epigenetic modifications and hormone signalling pathways which involves formation of protein complexes. With an improved understanding of these processes, plant breeders will be able to develop alternative strategies using genome editing technologies for crop improvement.