Pyrus betulifolia Bunge is a salt‑tolerant rootstock for pear, but its salt‑tolerance mechanisms remain largely unknown. In this study, P. betulifolia seedlings were subjected to graded NaCl stress at concentrations of 0 (CK), 50 (T1), 100 (T2), and 200 (T3) mM. We integrated phenotypic observation, physiological assessment, transcriptomic profiling, and functional gene validation to systematically elucidate its salt tolerance mechanisms. Salt stress inhibited seedling growth and root traits in a concentration-dependent manner, and T3 caused the most severe damage. Osmotic solutes responded differentially: soluble sugars peaked under T2, while proline peaked under T3. Antioxidant enzymes showed tissue-specific biphasic responses and declined after prolonged T3 stress. Meanwhile, chlorophyll and photosynthesis decreased, whereas anthocyanin increased, indicating a metabolic shift from photosynthesis to photoprotection. Transcriptome analysis revealed distinct responses depending on stress intensity: mild stress induced membrane lipid remodeling, moderate stress activated circadian rhythm and hormone signaling, and severe stress enhanced phenylpropanoid biosynthesis and thiamine metabolism. Gene Set Enrichment Analysis (GSEA) further highlighted progressive enrichment of phenylpropanoid biosynthesis, heme binding, and oxidoreductase activity. Weighted Gene Co‑expression Network Analysis (WGCNA) identified a blue module significantly positively correlated with root traits, from which the hub gene PbSTY46 was identified. Functional validation via overexpression, loss‑of‑function mutants, and pharmacological interventions (MeJA/DIECA) confirmed that PbSTY46 acts through JA signaling to enhance antioxidant enzyme activities and thereby confer salt tolerance. Collectively, P. betulifolia adopts a “survival‑first” strategy that coordinates growth arrest, osmotic homeostasis, and ROS scavenging. These findings establish PbSTY46 as a key regulator that links JA signaling to antioxidant defense. Thus, PbSTY46 represents a promising candidate for marker‑assisted breeding of salt‑tolerant pear cultivars.

Stone cells serve as pivotal determinants of pear fruit quality, with their formation exhibiting a strong correlation with lignification processes. As a phenolic signaling molecule with multiple biological functions, salicylic acid (SA) plays essential roles in regulating fruit growth and developmental processes. Nevertheless, the molecular mechanisms underlying SA-mediated modulation of stone cell differentiation in pears remain poorly characterized. Our investigation revealed that exogenous application of 15 mg L-1 SA decreased lignified stone cell formation in 'Nanguo' (Pyrus ussuriensis) pear fruits and significantly downregulating the expression of the lignin biosynthesis-related PuPRX64. mRNA-seq identified two transcription factors, PuWRKY29 and PuMYB62, which were significantly induced by SA. Functional characterization through transient expression assays in pear fruits and stable transgenic calli demonstrated that both factors act as negative regulators of stone cell formation and lignin accumulation. PuWRKY29 binds to the W-box cis-element within the PuMYB62 promoter to activate its transcription, while simultaneously forming a protein complex that synergistically represses PuPRX64 expression. Collectively, our findings suggest that exogenous SA treatment inhibits stone cell and lignin biosynthesis in pears via the PuWRKY29-PuMYB62 regulatory module.

Lignin deposition in stone cells is a critical factor that limits pear fruit quality, affecting their market value. Calcium ions (Ca 2+) play an essential role in lignin biosynthesis during fruit stone cell production. However, the genetic mechanisms underlying the Ca 2+ regulated lignin synthesis in stone cell formation are not fully understood. In this study, we identified an NAC transcription factor (TF) PuNAC21, which is repressed by CaCl2 treatment. PuNAC21 bound directly to the lignin biosynthesis gene peroxidase 42-like (PuPRX42-like) promoter, Ca2+ reduced pear fruit stone cell production dependent on PuNAC21 positively regulating PuPRX42-like expression. Furthermore, PuNAC21 directly regulated the expression of PuDof2.5, a TF involved in lignin biosynthesis by binding to PuPRX42-like and caffeoyl-CoA-O-methyltransferase 1(PuCCoAOMT1) promoters. Moreover, PuNAC21 interacted with PuDof2.5 to form a transcriptional regulatory module, lowering the transcription of PuPRX42-like and PuCCoAOMT1 after Ca2+ treatment, which contributed to decrease pear stone cells production. Our results revealed Ca2+-induced PuNAC21-PuDof2.5-PuPRX42-like/PuCCoAOMT1 regulatory module inhibited lignin biosynthesis, giving important insights into reducing the stone cell content in pears via molecular breeding.

Stone cells are one of the limiting factors affecting pear fruit quality and commodity value. The formation of stone cell is highly correlated with lignin deposition. However, the molecular mechanism of stone cell formation and regulation is still unclear. Here, we observed that exogenous application of GA significantly inhibited the formation of stone cells and also decreased the content of lignin in 'Nanguo' (Pyrus ussuriensis) pear fruits. The key gene PuPRX73 involved in the lignin synthesis pathway was further identified using RT-PCR, and GA-treatment significantly inhibited the expression of PuPRX73. Overexpression or silencing of PuPRX73 in pear fruits significantly increases or decreases the content of stone cells and lignin. We identified the transcription factors PuMYB91 and PuERF023 using mRNA-seq and their expression was significantly decreased after GA-treatment. Transient overexpression of PuMYB91 and PuERF023 promotes lignin and stone cells content in pear fruits, while silencing of PuMYB91 and PuERF023 led to the opposite results and inhibited the expression of PuPRX73. Yeast one-hybrid (Y1H) and GUS activity analysis revealed that PuMYB91 and PuERF023 directly bind and activate the PuPRX73 promoter, and co-transfection of PuMYB91 and PuERF023 in Nicotiana benthamiana leaves further promoted the promoter activity of PuPRX73. Furthermore, we found that PuMYB91 interacted with PuERF023 in vitro by using Yeast two-hybrid assays (Y2H). In conclusion, our results revealed that exogenous GA-treatment inhibits stone cell production by suppressing the expression of PuMYB91 and PuERF023 in pear fruits.

The differentiation of flower buds, powered by leaf photosynthesis, is a critical phase in a plant’s lifecycle. The transition of leaf color from green to red in ‘Nanguo’ pears symbolizes a redistribution of nutrients, which can significantly affect the quality of the buds. This research delves into the physiological, biochemical, and molecular underpinnings of this color transition, aiming to uncover its relationship with bud quality. This study performs a comparative analysis of the pigment composition, antioxidant enzyme activity, photosynthetic capacity, chlorophyll fluorescence traits, and soil physicochemical characteristics in both red and green leaves of ‘Nanguo’ pears. It also utilizes transcriptomic sequencing to examine the leaves. Moreover, the research delves into the sugar, mineral, and hormone concentrations within the axillary flower buds at the corresponding nodes, uncovering the physiological relationships that link leaf color transitions to the quality of flower buds. Red leaves had higher anthocyanin, hydrogen peroxide, malondialdehyde, and peroxidase activity than green leaves. However, green leaves displayed higher chlorophyll, photosynthetic rate, and stomatal conductance. Soil analysis under red leaves showed lower pH, phosphorus, potassium, and alkali-hydrolyzable nitrogen content. Transcriptomic data linked leaf color change to secondary metabolite pathways and plant hormone signaling. Flower buds adjacent to red leaves had reduced sugar, mineral, and hormone levels compared to those near green leaves. Enhancing red leaf photosynthesis and antioxidant defenses through soil nutrient management, hormone signaling, and secondary metabolite pathway regulation could improve ‘Nanguo’ pear bud development, fruit quality and yield.

The improvement of fruit quality, in particular sugar content, has been a major goal of plant breeding programmes for many years. Here, 2 varieties of the Ussurian pear (Pyrus ussuriensis), Nanguo, and its high-sucrose accumulation bud sport, Nanhong, were used to study the molecular mechanisms regulating sucrose transport in fruits. Comparative transcriptome analysis showed that in Nanhong fruit, an MYB transcription factor, PuMYB12, and a sucrose transporter protein, PuSUT4-like, were expressed at higher levels, while a paclobutrazol resistance transcription factor, PuPRE6, and a histone deacetylase (HDAC), PuHDAC9-like, were expressed at lower levels in Nanguo fruit. PuSUT4-like silencing and overexpression experiments in Nanguo pear showed that PuSUT4-like is essential for sucrose transportation. PuPRE6 and PuMYB12 act as antagonistic complexes to regulate PuSUT4-like transcription and sucrose accumulation. The histone deacetylation levels of the PuMYB12 and PuSUT4-like promoters were higher in Nanguo fruit than in Nanhong fruit, and Y1H assays showed that HDAC PuHDAC9-like bound directly to the promoters of PuMYB12 and PuSUT4-like. Our results uncovered transcription regulation and epigenetic mechanisms underlying sucrose accumulation in pears.

Soil salinization is a critical issue that not only hampers the efficiency and sustainability of global agricultural production but also poses significant challenges to the achievement of sustainable development goals across environmental, economic, and social dimensions. Halotolerant plant growth-promoting rhizobacteria (HPGPR) have the potential to mitigate abiotic stress, foster plant growth, and bolster the stress resistance capabilities of crops. This study conducted the isolation, identification, and characterization of HPGPR originating from a saline-alkali orchard area in northwest China. The efficacy of the isolated bacterial strains was evaluated through potted plant experiments, assessing the growth of tomato plants under in vitro conditions and under varying salinity stress. Ultimately, the study investigated the influence of these HPGPR on soil physicochemical properties, enzymatic activities, and the structure and composition of the microbial community. Upon isolating 12 bacterial strains, we conducted an in vitro assessment of their salt tolerance, ultimately singling out three robust isolates, which exhibited exceptional salt tolerance. Detailed 16S rRNA gene sequencing and meticulous taxonomic evaluation systematically assigned these isolates to Priestia endophyticus GSCK1 (accession number: OR569048), Bacillus atrophaeus GSCK2 (accession number: OR569061), and Serratia fonticola GSCK6 (accession number: OR569062), respectively. These strains exhibited notable biochemical and plant growth-promoting traits, including enzymatic activities and the production of indole-3-acetic acid. They significantly enhanced plant growth metrics and soil fertilities, particularly strain GSCK6, which also reshaped the soil microbial community, augmenting beneficial microbe abundance. The HPGPR treatment notably improved soil pH, nutrient availability, enzymatic activities, and reduced soil electrical conductivity, underscoring their potential in agricultural resilience against salinity. The eco-friendly salt stress mitigation strategy of HPGPR not only enhances soil quality and promotes plant growth by regulating the composition and function of microbial communities, but also provides a novel solution for global agricultural production. This approach is conducive to increasing crop yield and quality, reducing the limitations of saline-alkali land on agricultural production, and promoting food security and sustainable agricultural development.

BACKGROUND: Nanguo pear is a distinctive pear variety in northeast China, grown mainly in mountainous areas. Due to terrain limitations, ground-based pesticide application equipment is difficult to use. This limitation could be overcome by using unmanned aerial vehicles (UAVs) for pesticide application in Nanguo pear orchards. This study evaluated the spraying performance of two UAVs in the Nanguo pear orchards and compared them with a manually used backpack electric sprayer (BES). The study also analyzed the effect of canopy size on droplet deposition and ground loss, and evaluated two sampling methods, leaf sampling and telescopic rod sampling. RESULTS: Compared to BESs, droplet deposition is lower for UAVs, but the actual pesticide active ingredient deposition is not necessarily lower given the solution concentration. The droplet deposition varies among different UAVs due to structural differences. Under the same UAV operating parameters, droplet deposition on trees with smaller canopy sizes is typically greater than that on trees with larger canopy sizes, and the ground loss was also more severe. Although telescopic rod sampling is a quick and convenient method, it can only reflect the trend of droplet deposition, and the data error is greater compared with leaf sampling. CONCLUSION: UAVs can achieve better droplet deposition in mountainous Nanguo pear orchards and does almost no harm to the operators compared with the BES. However, canopy size needs to be considered to adjust the application volume rate. Telescopic rods can be used for qualitative analyses, but are not recommended for quantitative analyses. (c) 2024 Society of Chemical Industry.

Fruit ripening is a complex physiological and metabolic process regulated by plant hormones. The ripening of climacteric fruits is accompanied by softening, especially ‘Nanguo’ pear. The importance of ethylene in fruit softening is well established; however, an understanding of its effects during the later stages of fruit development requires further investigation. In this study, ethylene was sprayed on ‘Nanguo’ pear fruits before harvest resulting in enhanced fruit quality by increasing the soluble solid and sugar contents while decreasing the stone cell content. Additionally, ethylene promoted the activities of polygalacturonase, pectin methylesterase, cellulase, and β-galactosidase enzymes that play a critical role in cell wall metabolism, by up-regulating PuPG and PuPG2 expression. This leaded to changes in the cell wall structure and breakdown of its components, a reduction of cellulose and original pectin content, and an increase in water-soluble pectin content. These results indicate that ethylene enhances fruit softening by up-regulating the expression of genes involved in cell wall metabolism to facilitate the activity of cell wall degrading enzymes.

孔雀是沈阳农业大学从海棠品种绚丽实生苗中选育的品种.树姿直立,幼嫩叶片红褐色,被茸毛,成熟叶片绿色.花量极大,花蕾为红色.平均花芽率为83.0％,花序坐果率为100.0％.果实长圆锥形,萼片聚拢宿存,幼果为深红色,成熟后为亮红色,果面光滑,具有独特的观赏价值.

为明确除草剂乙草胺胁迫对草莓根系线粒体膜功能及保护酶系统活性的影响,探究土壤施加生物炭对减缓乙草胺胁迫对草莓根系线粒体功能伤害的保护机制.以盆栽"宝交早生"草莓(Fragaria×ananassa Duch.'Hokowase')为试材,设置乙草胺处理、乙草胺+生物炭处理及清水对照3个处理,测定处理后9 d内根系相关指标的变化.结果表明,乙草胺胁迫导致根系线粒体膜透性增大,根系线粒体膜电位Δφm下降,根系活力和H+-ATPase含量降低,O2-、H2O2产生速率持续升高,保护性酶SOD、POD活性持续增长,MDA含量不断增加.乙草胺胁迫能够破坏草莓根系线粒体膜结构,增加细胞质膜过氧化程度,造成线粒体膜功能下降.土施生物炭能有效缓解乙草胺胁迫对线粒体膜功能的伤害,提高草莓植株对乙草胺的适应能力.

Stone cells are sclerenchyma cells formed by deposition of lignin, which is the most significant factor limiting the quality of pears. Ca2+ was known to inhibit stone cells in pear fruits, but the underlying molecular mechanism remains unclear. Our study revealed that exogenous CaCl2 (Ca2+) treatment of "Nanguo" pear (Pyrus ussuriensis) suppressed the synthesis of lignin and stone cell production. We further analysed the transcriptomes using RNA-seq, identified a transcription factor, PuDof2.5, and its targets gene PuPRX42-like (lignin polymerase gene) expression decreased in CaCl2-treated samples, which are involved in suppressing lignin biosynthesis in pear fruit. PuDof2.5 was found to bind directly to the PuPRX42-like promoter and induced its transcription. Taken together, our results revealed that Ca2+ modulated the key lignin biosynthetic transcription factor PuDof2.5 to suppress stone cell production in pear fruits.

Owing to the specific selectivity, long persistence and effective weed control, acetochlor is widely used in agricultural production. However, the improper use of acetochlor in the strawberry breeding process can damage the growth and development of seedlings. Mitochondria is the primary site for sensing external signals, providing energy for all physiological activities in cells, and also the site producing the most ROS. Changes in membrane structure and function are closely related to plant tolerance. There are few studies on the damage mechanism of mitochondrial membrane structure and function in crop roots. In view of this pain point, Strawberry plants were used as experimental materials, the experiment comprised two treatments: an acetochlor treatment and a control treatment. Measured the changes of relevant indexes of root system within 9 days after treatment and study the effects of ROS induced by acetochlor on the structure and function of the mitochondrial membrane potential and membrane permeability in the roots of strawberry.

Fruit tree shoots are potential useful resources that are rich in carbohydrates and inorganic nutrients but that are not typically utilized in sustainable agriculture. Our objective was to evaluate the soil properties and soil quality of an orchard after returning apple shoots in situ and to investigate the contribution rate of apple shoots as an exogenous source of organic carbon for fertility amendment of the apple root domain. One-year-old apple shoots were pruned in spring before budding, chopped into 10 cm sections and placed on the soil surface. Soil samples were collected in the first year and third year after returning the shoots. Principal component analysis, Pearson correlation analysis and soil quality index (SQI) comprehensive analysis methods, combined with fuzzy mathematics, were adopted to evaluate the effects of returning apple shoots on comprehensive soil quality, including the soil fertility indicators, soil exchangeable cations, soil neutral sugar and amino acids. Increases in soil organic carbon (SOC), available potassium (K), and available phosphorus (P) were observed in different layers of the orchard soil with returned shoots over time. The total nitrogen (N) content decreased by 18.75% and 13.79% in the 0–20 cm and 20–40 cm soil layers, respectively, in the first year, but increased significantly in the third year. Significant increases in exchangeable cations (Na+, Ca2+, Mg2+) in the 0–20 cm soil layer were also observed in the third year after returning shoots, compared to the control. In addition, obvious accumulation of glucose and xylose was observed in the 0–20 cm soil layer compared to the controls in the third year after returning shoots. The total water-soluble free amino acid contents in the third year after returning shoots were 1.08- and 1.16-times higher, respectively, than those of the controls in the 0–20 cm and 20–40 cm soil layers. The SQI in the third year was higher than that of the other treatments in the 0–20 cm soil layer. This study suggests that abandoned apple shoots used as a supplementary carbon source for orchards enhanced the soil fertility of different soil layers, regulated the soil micro environment, and improved the overall soil quality.

石细胞是影响梨果实品质的关键因素之一,钙与石细胞次生壁形成过程关系密切.以南果梨为试材,于花后不同时期喷施钙肥,研究了不同浓度的氯化钙及糖醇螯合钙对其果实品质及石细胞代谢的影响.结果表明,与对照相比,不同钙肥处理对南果梨果实品质均有所改善,同时显著提高果实钙含量,并对石细胞形成有不同程度的抑制作用.其中,盛花期后20 d喷施5.0 g/L氯化钙可显著增加南果梨单果重、横纵径和总钙含量,并减少石细胞积累,效果最佳.进一步研究发现,氯化钙处理降低了木质素合成相关基因PuC3H、PuCAD、PuPOD、PuLAC的表达水平.因此,钙处理可通过抑制木质素途径下游基因的表达来减少石细胞的积累,是提高南果梨果实品质的有效措施.

Pyrus ussuriensis is the most important cultivated pear in the northeastern, cold areas of China. However, studies on the biological activity of Pyrus ussuriensis fruit are rare in the public domain. The present study compared antioxidant, anti-inflammatory, and antimicrobial activities and chemical composition in tissues from the peel and flesh of nine Pyrus ussuriensis cultivars. The chemical composition differed among cultivars and tissue sources. Phenolics were predominant in peel samples, whereas sugars were predominant in flesh samples. Twenty-one phenolic compounds were identified and quantified, including hydroxycinnamic acids, hydroquinones, flavanols, flavonols, flavones, and anthocyanins (only in peel samples). The total phenolic content ranged between 363.0 and 1734.0 mg kg− 1 FW in the peel and from 28.5 to 182.3 mg kg− 1 FW in the flesh. In addition, cultivars with high total phenolic and flavonoid contents had significantly higher antioxidant activities. The in vitro anti-inflammatory study, performed using an egg albumin denaturation assay, demonstrated that both peel and flesh samples had strong activity, which was comparable with that of the standard anti-inflammatory drug diclofenac sodium. The antimicrobial results showed that ‘Jianba’ and ‘Balixiang’ cultivars exhibited strong activity against bacteria strains in the peel and flesh, respectively. The present study provided information for selecting promising Pyrus ussuriensis cultivars with improved health benefits.

秋子梨是我国东北寒地主要的梨栽培种类,但关于其品质、酚类成分及生物活性的研究较少.选取6个秋子梨品种,对其果皮和果肉中的主要化学成分(糖、有机酸、酚类)及生物活性(抗氧化、抗炎和抑菌效果)进行分析和比较.结果表明:不同品种和部位(果皮和果肉)的化学成分差异显著.果皮的酚类含量、抗氧化能力和抑菌效果明显高于果肉,而糖含量则相反.南果梨的果实糖含量最高,京白梨的果皮中有机酸含量最高,尖把梨的果实中黄烷醇和槲皮素衍生物含量最高,而安梨果实则含有丰富的异鼠李素衍生物.试验共鉴定出16种酚类物质,包括羟基肉桂酸、对苯二酚、黄烷醇、黄酮醇和花青素(仅在果皮中).不同品种的果皮总酚含量为354.18～1190.14mg·kg-1,果肉总酚含量为28.27～182.11mg·kg-1,而总酚和总黄酮含量较高的品种也具有较高的抗氧化活性.抗炎活性研究表明,果皮和果肉提取物均具有较强的活性,与标准药物双氯芬酸钠活性接近.抑菌试验表明,尖把梨和红花盖的果实提取物具有较强的抑菌活性.研究结果可为秋子梨的资源应用和功能性食品研发提供参考.

Anthocyanins are important components in the peel of red pears and contribute to the appearance of the fruit. Melatonin application is known to affect anthocyanin biosynthesis, but the effect of preharvest melatonin application on fruit coloration remains largely unknown. The objective of this study was to determine the effects of preharvest melatonin application on pigmentation, phenolic compounds, and the expression of related genes in Nanhong pear (Pyrus ussuriensis). The applications were performed during the pre-color-change period by spraying 50 or 200 µmol L−1 of melatonin on fruits. We found that treatment with melatonin had a significant effect on color development. The concentrations of anthocyanins and flavonols were enhanced by melatonin treatment, whereas hydroxycinnamate and flavanol concentrations were reduced. Quantitative real-time PCR analyses indicated that the transcription levels for most anthocyanin biosynthetic genes and anthocyanin-related transcription factors were induced by melatonin. Melatonin application also stimulated the expression of melatonin biosynthesis-related genes and consequently caused an increase in endogenous melatonin concentration. These results provide insights into melatonin-induced fruit coloration and will facilitate the application of exogenous melatonin in agriculture.

为筛选适合'南果梨'疏果的化学药剂和喷施时期,以'南果梨'为试材,使用萘乙酸、多效唑、乙烯利等化学药剂,设计不同的化学药剂处理组合,于'南果梨'花后不同时期进行喷施.结果 表明:从'南果梨'的坐果率、脱萼率和果实品质综合来看,在盛花期喷施1次10 mg/L萘乙酸+500 mg/L多效唑+10 g/L氯化钙+2g/L磷酸二氢钾处理的效果最好,花朵坐果率和花序坐果率分别为16.50％、29.17％,脱萼率为80.65％,'南果梨'果实石细胞含量减少,可显著提高果实品质.

[目的]连作障碍是设施草莓(Fragariaxananassa Duch.)生产中遇到的严重问题,根系分泌的酚酸类物质是引起连作障碍的因素之一.本研究旨在探讨连作草莓植株的根系线粒体功能对自毒酚酸物质胁迫的生理响应,为进一步研究草莓连作障碍的生理适应机制奠定基础.[方法]本研究以草莓为试材,分别外源施加27.0 μg·g-1 丁香酸、邻苯二甲酸及两者混合溶液,借助电子显微成像、组织化学染色、液相氧电极等技术,观察根系活性氧含量变化,测定线粒体氧化磷酸化水平、呼吸途径及呼吸关键酶活性等指标的变化,研究自毒酚酸物质诱导的活性氧对根系线粒体功能的影响,探究根系线粒体参与的呼吸复合体代谢和能量代谢等生理功能的影响.[结果]施加2种外源酚酸及混合溶液处理均能导致草莓根系活力明显下降,显著影响根系总根长、总表面积、根系总体积和平均直径,抑制根系的发生和生长,抑制作用表现为丁香酸处理(D)＞两种溶液混合处理(D+L)＞邻苯二甲酸处理(L)＞CK.在草莓根系受到外界酚酸胁迫时,随着胁迫时间的延长,H+-ATPase活性前期呈现显著下降趋势,处理第3天时下降幅度最大,处理D、处理L、处理D+L分别比对照下降了38.8％、28.8％、33.7％,阻碍根细胞内外离子的运转能力,后期变化趋于平稳.根系K+Na+-ATPase及Ca2+Mg2+-ATPase活性也一定程度降低,变化规律相似.随着处理时间的延长,根系中超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)及抗坏血酸过氧化物酶(APX)活性均呈现显著下降趋势,H202和02+含量逐渐升高,根系线粒体MPT增大,降低Δψm及根系线粒体内膜上细胞色素Cyt c/a含量,破坏线粒体内膜细胞完整性和电子传递链,其中D处理效果最为显著.在草莓植株受到外源酚酸胁迫后,根系呼吸途径虽仍以EMP-TCA途径为主,但贡献率却显著降低,而PPP途径呈现出明显的增强趋势.外源酚酸处理后期,随着胁迫时间的延长,各呼吸关键酶活性均受到抑制作用,呼吸途径比例发生改变,进而导致各呼吸途径受阻,变化程度表现为D＞D+L＞L＞CK.[结论]外源酚酸处理可导致植株根系活力降低,阻碍细胞内外各离子的运转能力,降低根系抗氧化酶活性及根系线粒体功能,各呼吸途径关键酶活性均降低,最终导致各呼吸途径受阻.