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Light use efficiency (LUE) characterizes the efficiency of vegetation in converting photosynthetically active radiation (PAR) into biomass energy through photosynthesis and is a critical parameter for gross primary productivity (GPP) in terrestrial ecosystems. Based on the eddy covariance measurements of a Chinese cork oak plantation ecosystem in northern China, the temporal variations in LUE were investigated, and biophysical factors were examined at time scales ranging from hours to years. Our results show that diurnal LUE first increased sharply before 8:30 and then decreased gradually until 12:00, thereafter increasing gradually and reaching the maximum value at sunset during the growing season. The daily and monthly LUE first increased and then decreased within a year and showed a substantial drop around June. The annual LUE ranged from 0.09 to 0.17 g C mol photon−1, and the multiyear mean maximal LUE was 0.30 g C mol photon−1 during 2006–2019. Only GPP (positive) and clearness index (CI) (negative) had consistent effects on LUE at different time scales, and the effects of the remaining biophysical factors on LUE were different as the time scale changed. The effects of air temperature, vapor pressure deficit, precipitation, evaporative fraction, and normalized difference vegetation index on LUE were mainly indirect (via PAR and/or GPP). When CI decreased, an increased ratio of diffuse PAR to PAR produced a more uniform irradiance in the canopy, which ultimately resulted in a higher LUE. Due to climate change in our study area, the annual LUE may decrease in the future but improving management practices may slow or even reverse this trend in the annual LUE in the studied Chinese cork oak plantation. [ABSTRACT FROM AUTHOR]

In the context of 'energy shortage', developing a novel energy-based power system is essential for advancing the current power system towards low-carbon solutions. As the usage duration of lithium-ion batteries for energy storage increases, the nonlinear changes in their aging process pose challenges to accurately assess their performance. This paper focuses on the study LiFeO4(LFP), used for energy storage, and explores their performance degradation mechanisms. Furthermore, it introduces common battery models and data structures and algorithms, which used for predicting the correlation between electrode materials and physical parameters, applying to state of health assessment and thermal warning. This paper also discusses the establishment of digital management system. Compared to conventional battery networks, dynamically reconfigurable battery networks can realize real-time monitoring of lithium-ion batteries, and reduce the probability of fault occurrence to an acceptably low level. [ABSTRACT FROM AUTHOR]

Background: Despite the existence of available therapeutic interventions for HIV-1, this virus remains a significant global threat, leading to substantial morbidity and mortality. Within HIV-1-infected cells, the accessory viral protein r (Vpr) exerts control over diverse biological processes, including cell cycle progression, DNA repair, and apoptosis. The regulation of gene expression through DNA methylation plays a crucial role in physiological processes, exerting its influence without altering the underlying DNA sequence. However, a thorough examination of the impact of Vpr on DNA methylation in human CD4 + T cells has not been conducted. Methods: In this study, we employed base-resolution whole-genome bisulfite sequencing (WGBS), real-time quantitative RCR and western blot to explore the effect of Vpr on DNA methylation of host cells under HIV-1 infection. Results: We observed that HIV-1 infection leads to elevated levels of global DNA methylation in primary CD4 + T cells. Specifically, Vpr induces significant modifications in DNA methylation patterns, particularly affecting regions within promoters and gene bodies. These alterations notably influence genes related to immune-related pathways and olfactory receptor activity. Moreover, Vpr demonstrates a distinct ability to diminish the levels of methylation in histone genes. Conclusions: These findings emphasize the significant involvement of Vpr in regulating transcription through the modulation of DNA methylation patterns. Together, the results of this investigation will considerably enhance our understanding of the influence of HIV-1 Vpr on the DNA methylation of host cells, offer potential avenues for the development of more effective treatments. [ABSTRACT FROM AUTHOR]

Stand density affects the potentially superior productivity of forest ecosystems directly by regulating the light and nutrient availability of trees. Understanding how stand density influences the growth and development of trees is crucial for supporting forest management in the context of climate change. We focused on Liriodendron chinense in experimental plantations created in 2003, with planting densities ranging from 277 to 10,000 trees per hectare at six plots. The leaf structure and photosynthetic capacity of L. chinense changed significantly under different stand densities, which had a negative impact on their biomass (leaf mass) and nutrient (total carbohydrate content) accumulation. Transcriptional differences were observed among samples from plots with different planting densities. The expression of 1784 genes was negatively dependent on stand density, participating mainly in the biological processes of "circadian rhythm", "carbon metabolism", and "amino acid biosynthesis". Furthermore, we identified a photosynthesis-related module and constructed a gene regulatory network to discover that the transcription factors of MYB and bHLH may have important roles in the transcriptional regulation of photosynthesis biosynthesis by activating or repressing the expression of petA (Litul.15G096200), psbE (Litul.10G033900), and petD (Litul.17G061600) at different stand densities. Our study quantified the impact of stand density on tree growth at physiological and molecular levels. Our observations provide theoretical support for plantation establishment of L. chinense. [ABSTRACT FROM AUTHOR]

We investigated tree growth in Robinia pseudoacacia plantations at Ansai in Shaanxi Province and at Ji-xian in Shanxi Province by comparing the tree-ring width, basal area increase (BAI), δ13C value, intrinsic water-use efficiency (iWUE), and stomatal regulation. We quantified the responses of tree growth and iWUE to climatic factors at each site. The tree-ring width at Ansai and Jixian decreased with stand age, whereas the BAI at Ansai increased, and that at Jixian decreased after the BAI peaked. The δ13C value and iWUE of trees at Jixian were higher than those at Ansai. The iWUE of trees at both sites was similar to the constant intercellular CO2 concentration/atmospheric CO2 concentration (Ci/Ca) scenario, indicating that the C; of trees was elevated with increasing Ca, while the stomata remained open. The BAI at Ansai was significantly positively correlated with highest temperature in May, relative humidity in June, precipitation in August, relative humidity in September, and standardized precipitation evapotranspiration index (SPEI) in September and October of current year, but negatively correlated with temperature in June. The BAI at Jixian was significantly positively correlated with SPEI in June and July, and lowest temperature in October of current year. The iWUE of trees at Ansai was significantly positively correlated with relative humidity and precipitation in June of the current year, but negatively correlated with minimum temperature in May, relative humidity in June, and temperature and maximum temperature in July of current year. A significant positive correlation between iWUE of trees at Jixian and lowest temperature in June of current year was detected. At the annual scale, the BAI of trees at Ansai was positively correlated with precipitation and SPEI, but no significant relationship was observed for trees at Jixian. However, the iWUE of trees at both sites was significantly affected by precipitation. Path analysis showed that SPEI and minimum temperature had a direct effect on BAI and iWUE of trees at Ansai, whereas precipitation and average temperature indirectly affected BAI and iWUE through SPEI. The highest temperature had a direct effect on tree growth at Jixian, whereas precipitation, minimum temperature, and average temperature had direct effects on iWUE. These results suggested that SPEI was the main climatic factor that affected the growth of R. pseudoacacia, while C; was an important physiological factor. Our results could provide reference for the protection and management of R. pseudoacacia plantations under climate change. [ABSTRACT FROM AUTHOR]

3-hydroxy-3-methylglutaryl-CoA reductase (HMGR), as the rate-limiting enzyme in the mevalonate pathway, is essential for the biosynthesis of shikonin in Lithospermum erythrorhizon. However, in the absence of sufficient data, the principles of a genome-wide in-depth evolutionary exploration of HMGR family members in plants, as well as key members related to shikonin biosynthesis, remain unidentified. In this study, 124 HMGRs were identified and characterized from 36 representative plants, including L. erythrorhizon. Vascular plants were found to have more HMGR family genes than nonvascular plants. The phylogenetic tree revealed that during lineage and species diversification, the HMGRs evolved independently and intronless LerHMGRs emerged from multi-intron HMGR in land plants. Among them, Pinus tabuliformis and L. erythrorhizon had the most HMGR gene duplications, with 11 LerHMGRs most likely expanded through WGD/segmental and tandem duplications. In seedling roots and M9 cultured cells/hairy roots, where shikonin biosynthesis occurs, LerHMGR1 and LerHMGR2 were expressed significantly more than other genes. The enzymatic activities of LerHMGR1 and LerHMGR2 further supported their roles in catalyzing the conversion of HMG-CoA to mevalonate. Our findings provide insight into the molecular evolutionary properties and function of the HMGR family in plants and a basis for the genetic improvement of efficiently produced secondary metabolites in L. erythrorhizon. [ABSTRACT FROM AUTHOR]

Hibiscus syriacus, a woody ornamental plant with great economic value, is vulnerable to salinity. Hence, its cultivation in saline areas is severely restricted. Although grafting H. syriacus onto H. hamabo rootstock can greatly improve H. syriacus's salt resistance, the photosynthetic response of H. syriacus to grafting and salt stress remains largely unknown. To address this question, self-rooted (Hs), self-grafted (Hs/Hs), and H. hamabo-grafted (Hs/Hh) H. syriacus were exposed to 0 or 300 mM NaCl. Salt significantly reduced the net and maximum photosynthetic rates, chlorophyll content, and maximum (Fv/Fm) and actual (ΦPSII) photochemical quantum yield of photosystem II (PSII), as well as the apparent electron transport rate, in Hs and Hs/Hs. However, these reductions were largely alleviated when H. syriacus was grafted onto H. hamabo. In line with the changes in the chlorophyll fluorescence parameters, the expression of genes encoding subunits of PSII and PSI in Hs/Hh was higher than that in Hs and Hs/Hs under saline conditions. Moreover, H. hamabo rootstock grafting upregulated the genes involved in the Calvin–Benson–Bassham cycle in H. syriacus under salt conditions. These results indicate that grafting can ameliorate the inhibition of salinity on the photosynthetic capacity of H. syriacus, mainly resulting from alleviated limitations on photosynthetic pigments, photochemical efficiency, and the Calvin–Benson–Bassham cycle. [ABSTRACT FROM AUTHOR]