2 nanoparticles(SiO₂-NPs, 20 nm particle size)and plant growth promoting rhizobacteria(PGPR)on the growth and physiology of Antirrhinum majus under low-temperature stress, this study used normal temperature( 25 ℃ day/18 ℃ night )as the control(CK). The biomass, leaf anatomical structure, chlorophyll content, chlorophyll fluorescence parameters, and photosynthetic physiological indices of A. majus were determined under low-temperature stress(7 ℃ day / 4 ℃ night, LT)after foliar spraying of SiO₂-NPs at three concentrations [S₁(50 mg·L^-1), S₂(100 mg·L^-1), S₃(200 mg·L^-1)] alone or in combined treatment with PGPR strain Bacillus pumilus. The results were as follows:(1)Low-temperature stress significantly reduced the plant height, stem diameter, biomass, palisade tissue thickness, spongy tissue thickness, and tissue structure tightness in A. majus leaves. Spraying different concentrations of SiO₂-NPs or combined PGPR treatment on leaves could alleviate the growth inhibition and improve the tissue structure tightness.(2)Compared with the single low-temperature stress treatment(LT), contents of chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids in A. majus treated with LT+S₂+PGPR increased by 25.6%, 38.5%, 29.3%, and 29.6%, respectively. The maximum photochemical efficiency of PS Ⅱ(F_v/F_m), actual photochemical efficiency of PS Ⅱ(φPS Ⅱ), and photochemical quenching coefficient(qP)in chlorophyll fluorescence parameters increased by 24.9%, 65.0%, and 37.8%, respectively, while the non-photochemical quenching coefficient(NPQ)decreased.(3)Low-temperature stress inhibited the increase of net photosynthetic rate(P_n), transpiration rate(T_r), and stomatal conductance(G_s)of A. majus. The LT+S₂+PGPR treatment had the most significant promoting effect on P_n, T_r, and G_s, which were 137.1%, 109.9%, and 156.9% higher than those under the LT treatment, respectively.(4)Spraying different concentrations of SiO₂-NPs or combined PGPR treatment on leaves could significantly increase the activities of phosphoenolpyruvate carboxylase(PEPC)and ribulose-1,5-diphosphate carboxylase(Rubisco)in A. majus leaves, reduce the content of abscisic acid(ABA)in leaves, and enhance leaf water potential(LWP)to alleviate the low-temperature stress experienced by A. majus. In summary, LT+S₂+PGPR treatment demonstrated optimal efficacy, exhibiting a synergistic effect that significantly enhanced the low-temperature tolerance of A. majus. This provides technical support for its early spring cold-resistant cultivation.]]> 2026/8/20 10:56:55 1, XU Xiaoyan², SUN Yingkun^3*]]> MA Jiamei¹, XU Xiaoyan², SUN Yingkun^3* 9true Craigia yunnanensis, a plant specieswith extremely small populations(PSESP)endemic to China, is listed as a National Class Ⅱ protected wild plant. To clarify the causes of regeneration failure — particularly the lack of sapling recruitment in natural populations — this study compared the photosynthetic characteristics, photosynthetic pigment contents, leaf epidermal traits, leaf anatomical structures, and leaf functional traits between seedlings(6-month-old)and young trees(8-year-old)cultivated in an experimental plantation. The results were as follows:(1)The maximum net photosynthetic rate(P_max)(12.00 μmol·m^-2·s^-1)and light saturation point(LSP)(1 360.40 μmol·m^-2·s^-1)of young trees were extremely significantly higher(P<0.01)than those of seedlings(5.69 μmol·m^-2·s^-1 and 839.61 μmol·m^-2·s^-1, respectively), whereas the light compensation point(LCP)of seedlings was lower(11.37 μmol·m^-2·s^-1), indicating a shade-tolerant strategy in seedlings and a light-demanding strategy in young trees.(2)Chlorophyll(Chl)and carotenoid(Car)contents in young trees were significantly or extremely significantly higher than that in seedlings(P<0.05 or P<0.01), and their leaves were thicker, with more developed palisade tissues, larger midrib vessel diameters, and bigger leaf area, higher specific leaf weight(SLW), and leaf dry matter content(LDMC).(3)Correlation analysis revealed significant or extremely significant positive correlations(P<0.05 or P<0.01)between P_max and leaf thickness, chlorophyll content, SLW, and LDMC. In conclusion, seedlings adapt to low-light understory environments, whereas young trees require higher light availability to sustain their elevated photosynthetic capacity. Insufficient understory light in natural habitats likely hinders the transition from seedlings to young trees, contributing to the species' endangered status. These findings provide essential scientific support for conservation and cultivation practices. It is recommended that thinning or canopy-opening measures be implemented to improve understory light conditions and promote population regeneration.]]> 2026/8/20 10:56:55 1, YANG Zhe^2,3, JIANG Haidu², WANG Yong¹, LIU Xiongsheng¹, PENG Lihui², WEI Lingzhi^2,3, CHAI Shengfeng^2*, WEI Xiao²]]> CHEN Fengfan¹, YANG Zhe^2,3, JIANG Haidu², WANG Yong¹, LIU Xiongsheng¹, PENG Lihui², WEI Lingzhi^2,3, CHAI Shengfeng^2*, WEI Xiao² 8true γ-aminobutyric acid(GABA)on mitochondrial function in root-zone of one-year M. baccata under sublow-temperature. Using M. baccata seedlings as experimental material, we subjected them to a root-zone sublow-temperature treatment at 5 ℃ and applied exogenous GABA(10 mmol·L^-1)or its metabolic inhibitor, vigabatrin(VGB, 0.1 mmol·L^-1), respectively. Mitochondrial membrane permeability, cytochrome c/a value, respiratory metabolic pathways, energy substance contents, and antioxidant enzyme activities in roots were measured at 0, 2, 4, 6, 12 and 24 h after treatment. The results were as follows:(1)Compared with the control, 5 ℃ sublow-temperature significantly increased mitochondrial membrane permeability, decreased the cytochrome c/a value, and enhanced total respiration rate, activities of the cytochrome pathway(CP)and alternative pathway(AP), along with induced upregulation of the alternative oxidase gene(AOX)expression.(2)Compared with sublow-temperature treatment alone, exogenous GABA treatment significantly improved mitochondrial membrane stability and c/a value, promoted CP respiration and its contribution rate, inhibited AP respiration and AOX gene expression, while maintaining higher adenosine triphosphate(ATP)content and energy charge level and reducing adenosine monophosphate(AMP)accumulation.(3)Exogenous GABA treatment also increased the activities of superoxide dismutase(SOD), peroxidase(POD), catalase(CAT)and ascorbic acid peroxidase(APX), decreased malondialdehyde(MDA)content, and enhanced root vigor.(4)VGB treatment aggravated mitochondrial membrane damage and energy metabolic disorder, and inhibited antioxidant enzyme activities. In summary, exogenous GABA effectively alleviates root-zone sublow-temperature stress injury in M. baccata roots by protecting mitochondrial membrane integrity, optimizing respiratory pathway allocation, maintaining cellular energy homeostasis and enhancing antioxidant capacity, and this effect depends on an intact GABA metabolic pathway. These findings provide a theoretical basis for improving cold tolerance of M. baccata roots and are of great significance for breeding cold-resistant apple rootstocks.]]> 2026/8/20 10:56:56 *]]> YU Miao, WANG Aiguo, ZHAO Yilu, MA Huaiyu^* 7true 3 )on the growth and physiology of Dahlia pinnata, and to provide a theoretical basis for the selection and utilization of D. pinnata cultivars in saline-alkali areas, four cultivars(‘Cream Peach', ‘Milk Coffee', ‘Cliff Inspiration', and ‘Double Gill')were subjected to four stress concentrations(0, 50, 100, 150 mmol·L^-1)in a pot experiment. Growth, photosynthetic parameters, osmotic adjustment, and antioxidant enzyme activities were measured at 7, 14, and 21 d after stress initiation. The results were as follows:(1)Saline-alkali stress significantly inhibited the growth of D. pinnata seedlings, and the inhibition increased with stress concentration and duration; significant differences were observed among cultivars, and the growth of the most saline-alkali tolerant cultivar ‘Double Gill' was much higher than that of the saline-alkali sensitive cultivar ‘Cliff Inspiration'.(2)With increasing saline-alkali stress, net photosynthetic rate, stomatal conductance, and transpiration rate all decreased significantly, while intercellular CO₂ concentration firstly decreased and then increased. Among the cultivars, ‘Double Gill' consistently maintained the highest net photosynthetic rate.(3)As stress concentration increased, leaf relative water content continuously decreased, but ‘Double Gill' still maintained a relatively high level of 66.4% under severe stress; malondialdehyde content increased sharply, and membrane lipid peroxidation aggravated. Meanwhile, proline and soluble sugars accumulated continuously. The antioxidant enzyme system was activated under mild and moderate stresses, but under severe stress, only ‘Double Gill' maintained high enzyme activity.(4)The concentration of 100 mmol·L^-1 was identified as the critical concentration for saline-alkali tolerant differentiation, at which the saline-alkali sensitive cultivar ‘Cliff Inspiration' exhibited irreversible damage.(5)There were significant differences in saline-alkali tolerance among cultivars(P<0.05). The membership function analysis ranked the saline-alkali tolerance in the following order: ‘Double Gill' > ‘Milk Coffee' > ‘Cream Peach' > ‘Cliff Inspiration'. In conclusion, the physiological adaptability of D. pinnata seedlings under mixed saline-alkali stress is cultivar-specific. The saline-alkali tolerant cultivar ‘Double Gill' maintains relatively stable physiological status under severe stress by sustaining higher photosynthetic capacity, water retention ability, and antioxidant enzyme activities, making it a promising candidate for greening in saline-alkali areas.]]> 2026/8/20 10:56:56 *]]> WANG Yaqin, LIU Wenlan^* 6true Ochroma lagopus is characterized by its fast growth, short life cycle, minimum wood density and uniform material texture, and is widely used in the wind power industry and the aviation industry. However, challenges such as low natural seed germination rates due to hard seed coat and prolonged seed dormancy, as well as high seedling variability restricted severely standardized breeding and large-scale cultivation. In order to improve the seeds germination, seedlings homogeneity and growth, this study performed dish germination and pot control experiments to evaluate the effects of varying concentrations of indoleacetic acid(IAA), 6-benzyl ademine(6-BA), and gibberellin(GA)on seed germination and seedling growth for O. lagopus. The results were as follows:(1)GA promoted seed germination and embryo growth, while IAA and 6-BA inhibited seed germination, the biomass and length of embryo bud and embryo root(P<0.05), and the inhibitory effect increased with the increasing of concentration.(2)On the contrary, GA, IAA and 6-BA boosted the growth of seedlings, and the promoting effect on ground diameter was greater than that on the height and root length, and the effect enhanced with the increasing concentration(P<0.05).(3)In addition, GA and IAA also significantly increased the below-ground biomass and root-shoot ratio of seedlings(P<0.01). This study concluded that GA enhanced seed germination by breaking seed dormancy, while GA, IAA and 6-BA not only facilitated the performance of seedlings but also increased the root-shoot ratio, ultimately accelerating their water absorption capacity and drought resistance. These findings provided a theoretical basis and practical reference for the seedling raising technology and cultivation management of O. lagopus.]]> 2026/8/20 10:56:56 1,2, ZHANG Jiazhen^2,3, ZHAO Zemin⁴, LÜ Junjie⁵, LI Tianliang⁶, CAO Xiongjiang^2,3, YANG Li^2,3, LI Guozhen^2,3, ZHAO Gaojuan^2*, CHEN Yajun^2,6]]> LI Mingyi^1,2, ZHANG Jiazhen^2,3, ZHAO Zemin⁴, LÜ Junjie⁵, LI Tianliang⁶, CAO Xiongjiang^2,3, YANG Li^2,3, LI Guozhen^2,3, ZHAO Gaojuan^2*, CHEN Yajun^2,6 5true 2-NPs)have demonstrated significant potential in enhancing plant stress resistance. To elucidate the regulatory mechanism of ZnO-NPs+SiO₂-NPs pretreatment on Eustoma grandiflorum under temperature stress, this study employed E. grandiflorum seedlings as materials and adopted an orthogonal experimental design [L₉(3⁴)]. Initially, the effects of ZnO-NPs+SiO₂-NPs on the growth of E. grandiflorum seedlings under different concentrations, proportions, and spraying times were investigated to screen the optimal spraying scheme. Subsequently, the seedlings were pretreated and subjected to high temperature(42 ℃ for 24 h)and low temperature(4 ℃ for 24 h)stress treatments, respectively. Physiological indicators and related stress-resistant gene expression were measured. The results were as follows:(1)When the total concentration of nanoparticles was 0.03%(m/V), the proportion of ZnO-NPs to SiO₂-NPs was 1:2(V/V), and the seedlings were sprayed twice on the leaves, the seedling growth was optimal.(2)The ZnO-NPs + SiO₂-NPs pretreatment increased the chlorophyll content of the leaves under normal growth condition, reduced relative electrical conductivity, malondialdehyde(MDA)content, and hydrogen peroxide(H₂O₂)accumulation under 42 ℃ and 4 ℃ stresses; enhanced the activities of superoxide dismutase(SOD), catalase(CAT), and peroxidase(POD).(3)ZnO-NPs+SiO₂-NPs pretreatment upregulated the expression levels of Mn-SOD, Cu/Zn-SOD, Fe-SOD, CAT, and POD genes.(4)Under 42 ℃ stress, ZnO-NPs+SiO₂-NPs pretreatment promoted the expression of heat shock protein 90 gene(HSP90); under 4 ℃ stress, it upregulated the expression of cold-regulated gene(COR413). In summary, suitable ZnO-NPs+SiO₂-NPs pretreatment effectively improves the growth status of E. grandiflorum seedlings and enhances their resistance to temperature stress by promoting increases in antioxidant enzyme activities and the expressions of related stress-resistant genes. This study reveals the molecular mechanism by which ZnO-NPs+SiO₂-NPs pretreatment enhances the resistance of E. grandiflorum to temperature stress, and provides a theoretical basis for the application of nanomaterials in flower stress-resistant research.]]> 2026/8/20 10:56:56 *]]> LIU Cheng, HAO Xuan, GAO Chengye, CHANG Yiman, WEN Jinfen^* 4true Pinus yunnanensis and its variety P. yunnanensis var. pygmaea, and to clarify their response differences and the feasibility of using smoke water as a fire signal mimic to stimulate tree growth and development. Seeds of two pines were treated with smoke water of different concentrations, and changes in their germination characteristics, embryo growth status, and related physiological indices were analyzed. The results were as follows:(1)The germination and physiological indices of two species seeds were significantly affected by the concentration of smoke water(P<0.05), showing a trend of promotion at low concentrations and inhibition at high concentrations.(2)The germination indices of two species peaked at 0.5%, at which the germination rate and germination energy of P. yunnanensis increased by 22.80% and 62.54%, respectively, while those of P. yunnanensis var. pygmaea increased by 12.50% and 110.83%, compared with control(distilled water treatment).(3)Two species differed in the optimal smoke water concentration for embryo growth. The longest hypocotyl and radicle of P. yunnanensis were observed at 1%(increased by 31.96% and 67.89%, respectively, compared with control), while those of P. yunnanensis var. pygmaea were observed at 0.25%(increased by 18.18% and 60.77%, respectively, compared with control).(4)At low concentrations, the smoke water enhanced the activities of α-amylase, protease, and lipase, increased soluble sugar and soluble protein contents, and reduced malondialdehyde content, thereby improving seed metabolism and antioxidant capacity.(5)P. yunnanensis seeds showed higher sensitivity to smoke water than P. yunnanensis var. pygmaea seeds. In conclusion, the smoke water promotes seed germination and embryo growth at low concentration by enhancing the mobilization of storage substances and regulating the antioxidant system, and thus can be applied as a safe and controllable fire signal mimic for seedling cultivation.]]> 2026/8/20 10:56:56 1,2, FU Guojiang1,2, TAO Jianghui1,2, HE Zhaoyun1,2, BO Kaimeng1,2, YAO Zengyu1,2*]]> ZUO Jiagen1,2, FU Guojiang1,2, TAO Jianghui1,2, HE Zhaoyun1,2, BO Kaimeng1,2, YAO Zengyu1,2* 3true 3^-/CO₃^2- stress)to ensure normal biochemical reactions. Moreover, plants respond to saline-alkaline stress by regulating the transcription of stress-responsive genes and transcription factors, coupled with triggering signal transduction pathways. Meanwhile, plant root exudates function as chemical signals to selectively recruit specific beneficial microorganisms in the rhizosphere. This recruitment process reshapes the diversity, composition, structure, and functional characteristics of the rhizosphere environment, constructing a rhizosphere microhabitat adaptive to saline-alkaline stress. Plant growth-promoting microorganisms(PGPM), recognized as the “second genome” of plants owing to their close symbiotic relationship with plants, enhance plant saline-alkaline tolerance through various synergistic mechanisms. These primarily include regulating plant hormone levels, controlling osmotic balance, enhancing the antioxidant defense system, maintaining ion balance, promoting nutrient absorption, and regulating metabolic pathways, thereby improving the plant's tolerance to salinity and alkalinity. PGPM can influence the assembly of the rhizosphere microbial community, promoting host plant growth and enhancing its stress tolerance by enriching beneficial microorganisms. This maintains their ability to promote plant growth and mitigate stress effects. This review systematically summarizes the morphological, physiological, molecular, and rhizosphere microbiological mechanisms by which plants respond to saline-alkaline stress. It highlights the pivotal role of PGPM in sustaining plant life under saline-alkaline conditions, provides a robust scientific foundation for sustainable agricultural development and ecological restoration in saline-alkaline regions.]]> 2026/8/20 10:56:56 1,2, WANG Jianfeng^3*, MA Lanmin², LI Hanxiao², JIANG Zhongyu², LIANG Jia², XU Wenmin², MA Lele², LI Ping^2*]]> WANG Li^1,2, WANG Jianfeng^3*, MA Lanmin², LI Hanxiao², JIANG Zhongyu², LIANG Jia², XU Wenmin², MA Lele², LI Ping^2* 2true Phytophthora leaf fall disease is one of the main diseases affecting rubber trees. In recent years, its prevalence and severity have continued to increase in rubber-growing areas of Yunnan, causing substantial economic losses to the local rubber industry. Because the disease occurs sporadically at the early stage and relevant research remains limited, precise standards for disease control and tapping cessation in infected trees have not yet been established. Therefore, this study aimed to develop a scientific indicator system for disease control and tapping cessation, so as to avoid pesticide waste and dry rubber yield loss caused by premature disease control and tapping cessation, and to prevent severe damage to rubber trees resulting from delayed control measures. Based on the variation patterns of latex physiological characteristics during disease progression, latex samples with disease severity grades 0-5 were systematically collected from seven farms and one township in the rubber-growing area of Xishuangbanna, Yunnan Province. The widely cultivated rubber tree clones GT1 and RRIM600 were selected as the study materials. The contents of sucrose, inorganic phosphorus, thiol, and total solids in latex were determined, and the changes in latex physiological parameters among trees with different disease severity grades were analyzed. The results were as follows:(1)With increasing disease severity, the contents of thiol, sucrose, and total solids in latex decreased significantly, whereas inorganic phosphorus content increased markedly. Among these parameters, only thiol content showed an extremely significant negative correlation with disease progression.(2)Based on the standard values determined in the preliminary study, the latex thiol content of RRIM600 decreased to 0.26 mmol·L^-1 at disease severity grade 3, while that of GT1 decreased to 0.35 mmol·L^-1 at disease severity grade 4; both values were at relatively low levels. In conclusion, latex thiol content can serve as a core indicator for disease control and tapping cessation in infected rubber trees. The tapping-cessation thresholds for RRIM600 and GT1 were determined to be 0.26 mmol·L^-1 and 0.35 mmol·L^-1, respectively. Considering the rapid progression of this disease, control measures are recommended to be initiated at disease severity grade 2(or when latex thiol content decreases to 0.31 mmol·L^-1)for RRIM600, and at disease severity grade 3(or when latex thiol content decreases to 0.42 mmol·L^-1)for GT1. This study introduces latex physiological diagnosis into the control system of Phytophthora leaf fall disease and provides new technical approaches and a theoretical basis for precise disease control and scientific tapping cessation.]]> 2026/8/20 10:56:56 1,2, GAO Qian^1,2, YANG Enshan^1,2, HU Yonghua^1,2, XIAO Zaiyun^1,2*]]> QIU Yanfen^1,2, GAO Qian^1,2, YANG Enshan^1,2, HU Yonghua^1,2, XIAO Zaiyun^1,2* 1true