几丁质和flg22诱导的辣椒幼苗先天免疫生理响应特征

【目的】为明确几丁质和鞭毛蛋白衍生肽flg22诱导的辣椒幼苗先天免疫生理响应特征,探讨辣椒先天免疫生理响应与辣椒抗多种病害的关系。【方法】以5个四川本地辣椒品种幼苗为试材,鉴定它们对青枯病和疫病病情指数和抗性水平,采用水培法培育幼苗并进行外源几丁质和flg22处理,检测各品种不同诱导时间下幼苗根系生长、气孔孔径、胼胝质沉积、活性氧(ROS)积累和SOD、CAT活性,以及先天免疫相关基因表达量的变化,综合评价其生理响应及其与抗病性关系。【结果】(1)各品种幼苗青枯病和疫病病情指数以‘川腾10号’最低,抗病性最强,以‘本地条椒’最高,抗病性最弱。(2)外源几丁质和flg22抑制了各品种幼苗根系生长速率,诱导离体叶片气孔闭合,促进叶片细胞壁胼胝质沉积加厚,ROS含量持续增加,SOD和CAT活性不断提高。各品种幼苗先天免疫生理响应指标的平均隶属函数值以‘川腾10号’最高,‘本地条椒’最低,并且平均隶属函数值与疫病、青枯病病情指数均具有显著负相关性。(3)外源flg22和几丁质诱导‘川腾10号’幼苗先天免疫相关基因CaWRKY22、CaMAPK7和ChiIV3显著上调表达。【结论】外源flg22和几丁质可诱导辣椒幼苗先天免疫生理响应,且响应程度强弱在品种间存在差异,依据生理响应指标通过隶属函数可综合评价辣椒品种的抗病水平;‘川腾10号’的平均隶属函数值最高,多抗性水平最好,这与其先天免疫相关基因CaWRKY22、CaMAPK7和ChiIV3的显著上调表达有关。

辣椒EIL基因家族的鉴定及其在盐碱胁迫下的表达分析

EIL(Ethylene-insensitive 3-like)基因在参与植物乙烯信号通路的转导和生长发育过程中发挥着重要作用。为了解辣椒EIL基因家族成员信息,利用生物信息学手段对辣椒EIL基因家族成员的理化性质、蛋白质结构、系统进化、基因结构、保守域、启动子顺式作用元件及CaEILs基因在不同组织部位和不同非生物胁迫条件下的表达模式进行分析。同时使用实时荧光定量PCR(qRT-PCR)对辣椒叶片中CaEILs在盐碱胁迫下的表达模式进行研究。结果表明,辣椒9个CaEILs分布在6条染色体上,氨基酸数目、蛋白质理论分子质量和脂肪系数分别介于209~677、23.77~76.07 ku和63.10~87.75,且主要为酸性、亲水的不稳定性核蛋白。系统进化分析显示,CaEILs被分成了4个亚家组,9个CaEILs在根、茎、叶、花蕾、花中具有不同程度的表达,而低温、高温、高盐、干旱胁迫下均能诱导CaEILs的表达,其对以上非生物胁迫均具有不同程度的响应。此外,利用qRT-PCR对盐碱胁迫下辣椒叶片中CaEILs进行了检测,结果发现,随着处理时间的延长,CaEIL1、CaEIL2、CaEIL4、CaEIL5、CaEIL8的表达量整体呈上升趋势,而CaEIL3、CaEIL6、CaEIL7、CaEIL9的表达量整体呈下降趋势。

Combining Transcriptomics and Metabolomics to Uncover the Effects of High-Energy Lithium-Ion Beam Irradiation on Capsicum annuum L.

Hot pepper(Capsicum annuum L.)is consumed as one of the oldest domesticated crops all over the world.Although mutation breeding using radiation has been performed in hot peppers,little is known about the comparative analysis of mutagenic effects at the molecular level by ion beam irradiation.To comprehend the response mechanism of hot pepper to the ion beam,we used a mutant with favorable economic characteristics induced by lithium-ion beam irradiation to investigate the biological effects.The results indicated that the lithium-ion beam had a positive effect on important agronomic traits,particularly yield unit,but had a negligible effect on the photosynthetic rate of hot pepper,with a specific influence on chlorophyll b rather than chlorophyll a.By RNA-Seq analysis,671 up-regulated and 376 down-regulated genes were identified as differentially expressed genes(DEGs)between irradiated and unirradiated hot pepper.Based on GO and KEGG network analysis,the auxin metabolic process was the common pathway in these two networks.A total of 118 potential reactive oxygen species(ROS)scavenging genes and 262 signal transduction genes were identified,suggesting a balance between antioxidant enzymes and enhanced ROS transduction.The amounts of 15 metabolite,involved in GABA pathways,secondary metabolism,carbohydrate metabolism,shikimate pathways,TCA cycles,nitrogen metabolism,glycerol metabolism and acetate pathways,were significantly changed in the ion beam irradiated sample.These results highlighted that the enriched pathways could play important roles in response to ion beam irradiation in hot pepper plants.In summary,these data provide valuable information for future research on ion beam irradiation and genomic studies in hot pepper.

Effects of Microwave Blanching Treatment on POD Activity and Crispness in Capsicum frutescens L.

[Objective] To study the effects of microwave blanching treatment on POD activity and crispness in Capsicum frutescens L., and to compare the effects of microwave blanching method, normal blanching method, boiling water blanching and steam blanching. [Methods] In order to obtain the optimal condition for microwave blanching, response surface methodology was used to construct a quadratic regression model describing the effects of microwave power, microwave time and calcium lactate concentration on the POD activity in C. frutescens. [Results] The optimal technology was obtained based on central composite design： 525 W microwave power, 64.5 s microwave time, and 0.08% calcium lactate concentration. Under this condition, POD enzyme activity of C. frutescens was desactivated and crispness of C. frutescens was 68.77 N. [Conclusions] This research would provide references for the crispness protection and enzyme deactivation of C. frutescens.

五彩椒(Capsicum annuum L.)的组织培养研究

以抗寒性较强的五彩樱桃椒为试验材料,对观赏椒的组织培养进行了研究。试验表明,最佳外植体为茎尖,茎尖的最佳消毒时间为3min;最佳诱导培养基为MS+6-BA5mg·L-1+NAA1mg·L-1;最佳分化培养基为MS+6-BA5mg·L-1+NAA0.1mg·L-1,最佳生根培养基为1/2MS+IBA0.25mg·L-1。

Effect of Different Culture Conditions on Sporulation Quantity of Phytophthora capsici in Capsicum annuum L. var. dactylus M. in Xunhua

[Objective] The paper was to explore the effect of different culture conditions on sporulation quantity of Phytophthora capsici in Capsicum annuum L.var.dactylus M.in Xunhua.[Method] The effects of light hours,pH,medium and temperature on sporulation quantity during isolation and culture process of P.capsici were studied.[Result] The sporulation quantity of P.capsici under the conditions of 24 h/day light,pH 7.0,potato medium（PSA） and 30 ℃ was the largest,and pH,basal medium and temperature had greater impact on sporulation quantity.[Conclusion]The study laid foundation for the study on natural incidence condition of C.annuum in Xunhua.

与辣椒抗TMV L^(3)基因连锁的分子标记的筛选及种质资源抗TMV鉴定

以含抗辣椒TMV的L^(3)基因的材料L15为基础,利用与L^(3)基因连锁的3个分子标记189D23MF、PMFR11和PMFR21对种质资源进行鉴定.对L15、3份感病材料H8/H9/H11×L15 F_(1)、46份辣椒种质资源进行室内人工TMV接种并对其进行表型抗性鉴定和RT-PCR检测.对筛选出的标记在F_(1)及BC_(1)P_(1)群体中进行验证.结果表明:分子标记189D23MF在L15和12份辣椒种质上均未扩增出条带;SCAR标记PMFR11在L15和46份辣椒种质上呈现共显性分离,SCAR标记PMFR21为显性标记.通过室内人工接种鉴定方式,2份材料L15、H11×L15表现为高抗.H9×L15表现为抗,H8×L15及5份材料A1、A35、A39、A55、L16表现为中抗,11份材料表现为感病,30份材料表现为高感.在F1及BC1P1群体中PCR扩增结果表明SCAR标记PMFR21可用于辣椒抗TMV分子标记辅助选择.

气孔在辣椒(Capsicum annuum L.)子叶和下胚轴上的动态变化

以辣椒幼苗(Capsicum annuum L.)为材料,研究了辣椒生长发育过程中子叶的上、下表皮和下胚轴上、下端1 cm处的气孔密度及表皮细胞密度的动态变化。结果表明:(1)辣椒的气孔由肾形保卫细胞组成,无副卫细胞;子叶的表皮细胞呈无规则形,下胚轴的表皮细胞呈长方形或椭圆形;(2)辣椒子叶上、下表皮的气孔密度和表皮细胞密度分别在辣椒种子出芽后第6天和第3天达到最大,之后随子叶的生长逐渐减小,下表皮的气孔密度和表皮细胞密度明显大于上表皮的;(3)辣椒下胚轴上、下端1 cm处的气孔密度随下胚轴的生长变化不明显,但是表皮细胞密度随下胚轴的生长逐渐减小,下胚轴上端的气孔密度和表皮细胞密度明显的大于下胚轴下端的。

Effects of Chlorine Dioxide Gas on Postharvest Physiology and Storage Quality of Green Bell Pepper (Capsicum frutescens L.var.Longrum)

The effects of treatment of chlorine dioxide （C1Oz） gas on postharvest physiology and preservation quality of green bell peppers were studied. Green bell peppers were collected in bags and treated with 0, 5, 10, 20, and 50 mg L^-1 ClO2 gas at 10±0.5℃ for over 40 d, and the changes in postharvest physiology and preservation quality of the peppers were evaluated during the storage. The inhibition of rot of the peppers was observed for all the tested ClO2 gas treatments. The rot rates of the treated samples were 50% lesser than those of the control after day 40 of storage. The highest inhibitory effect was obtained after 50 mg L^-1 ClO2 gas treatment, where the peppers did not decay until day 30 and showed only one-fourth of the rot rate of the control at day 40 of storage. The respiratory activity of the peppers was significantly （P〈0.05） inhibited by 20 and 50 mg L^-1 ClO2 treatments, whereas no significant effects on respiratory activity were observed with 5 and 10 mg L^-1 ClO2 treatments （P〉0.05）. Except for 50 mg L^-1 ClO2, malondialdenyde （MDA） contents in the peppers treated with 5, 10, or 20 mg L^-1 ClO2 were not significantly （P〉0.05） different from those in the control. Degradation of chlorophyll in the peppers was delayed by 5 mg L-1ClO2, but promoted by 10, 20, or 50 mg L^-1 ClO2. The vitamin C content, titratable acidity, and total soluble solids of the peppers treated by all the tested ClO2 gas did not significantly change during the storage. The results suggested that ClO2 gas treatment effectively delayed the postharvest physiological transformation of green peppers, inhibited decay and respiration, maintained some nutritional and sensory quality, and retarded MDA accumulation.

Cloning and characterization of CaGID1s and CaGAI in Capsicum annuum L.

Fruit set and development are affected by many phytohormones, including gibberellin. Little is known regarding molecular mechanism underlying gibberellin mediated fruit set and development especially in Capsicum. Three gibberellin recep- tors, CaGIDlb.1, CaGIDlb.2 and CaGIDlc, and a DELLA protein, CaGAI, have been identified in Capsicum annuum L. During the fruit development, the expression level of CaGIDlc was low, and the expression fold change is mild. However, CaGIDlb. 1 and CaGIDlb.2 were relatively higher and more acute, which indicates that CaGIDlb. 1 and CaGID1b.2 may play an important role in fruit pericarp, placenta and seed. Ectopic expressions of CaGIDlb. 1, CaGIDlb.2 and CaGIDlc in Arabidopsis double mutant gidla gidlc increased plant height, among which CaGIDlb.2 had the most significant effect; CaGAI reduced plant height in double mutant rga-24/gai-t6, having a similar function to AtGID1 and AtGAI in stem elon- gation. Yeast two-hybrid （Y2H） and bimolecular fluorescence complementation （BiFC） assays indicated that CaGIDlb.1 and CaGID1 b.2 interact with CaGAI in a GA-dependent manner, while CaGIDlc interacts with CaGAI in a GA-independent manner. Our study reveals the key elements during gibberellin signaling in Capsicum and supports the critical importance of gibberellin for Capsicum fruit set and development.

Combining Ability Analyses of Net Photosynthesis Rate in Pepper (Capsicum annuum L.)

In perspective of breeding high-yield hybrid pepper varieties, combining ability analysis of net photosynthesis rate at different phases of flowering and fruit setting in pepper was made with 15 cross combinations from 6 parents by （1/2） n （n- 1） diallel crosses. There are relatively large differences not only in general combining ability （GCA） effect among different parents and at different phases of flowering and fruit setting, but also in specific combining ability （SCA） effect among different hybrids. There are relatively large GCA effects in late parents but relatively less GCA effects in early parents. No obvious laws have been found in the relationship between SCA effects and maturity of hybrids. Variances of SCA are larger than those of GCA. Heritability is less but influence of environment is larger. Correlation analysis of combining ability between net photosynthesis rate and agronomic character or resistances to main diseases has showed that correlation coefficients of GCA are relatively large at the medium phase and the late phase of flowering and fruit setting. Net photosynthesis rate is more relative to leaf characters and fruit characters. Correlation coefficients of SCA are relatively large at the early phase and the late phase of flowering and fruit setting. Net photosynthesis rate is more relative to leaf characters and plant characters at the early phase but to plant characters and fruit characters at the late phase. Correlation coefficients of SCA between net photosynthesis rate and resistances to main diseases are larger than those of GCA. The combining abilities of net photosynthesis rate at different phases of flowering and fruit setting are positively correlated with those of yield per plant. The combining ability is an important parameter of breeding of high photosynthesis hybrid pepper varieties.

Effect of continuous negative pressure water supply on the growth, development and physiological mechanism of Capsicum annuum L.

Effects of continuous negative pressure water supply on water consumption, growth and development, as well as physiological mechanism and quality of Capsicum annuum L. were investigated in this paper. Meanwhile, the optimal negative pressure water supply conditions for growth of C. annuum L. were screened out to achieve the goals of water conservation, high yield and high quality, thus providing theoretical foundation for its field production. The pot experiment within the greenhouse was utilized; the continuous negative pressure water supply was adopted; the four treatments, artificial watering（CK）, –5 k Pa（T1）, –10 k Pa（T2）, and –15 k Pa（T3） were set; and the daily water consumption, yield, as well as the biomass, nitrate reductase, root activity, vitamin C, capsaicin, and nutrient uptakes of nitrogen（N）, phosphorus（P） and potassium（K） during various stages of its growth were determined. Compared with CK, when the water supply pressure was controlled at –5 to –15 k Pa in the experiment, the total water consumption of C. annuum L. reduced by 53.42 to 67.75%, the total water consumption intensity reduced by 54.29 to 67.14%, and the water use efficiency increased by 12.66 to 124.67%. The N accumulation in a single strain of C. annuum L. from the color turning stage to the red ripe stage increased by 15.99 to 100.55%, respectively, compared with that of CK; the P accumulation increased by 20.47 to 154.00% relative to that of CK, and the K accumulation increased by 64.92 to 144.9% compared with that of CK. Compared with CK, C. annuum L. yield was remarkably improved by 13.79% at T1, and contents of vitamin C, capsaicin as well as carotenoids at all growth stages were enhanced by 13.42–147.01%, 11.54–71.01%, and 41.1–568.06%, respectively. Nitrate reductase activity, root activity and chlorophyll（a＋b） were markedly increased by 335.78–500%, 79.6–140.68% and 114.95–676.19%, respectively, from immature stage to full ripe stage. Adopting the continuous negative pressure water supply for C. annuum L. has a significant water-saving effect, and the water supply pressure being stable at –5 k Pa contributes to its growth and development, improves yield, enhances root activity, promotes nutrient uptake, and improves its quality, thus achieving the effects of water conservation, high yield, high quality and high efficiency.

Soil Manganese and Iron Released due to Calcium Salts:Bioavailability to Pepper (Capsicum frutescens L.)

Releases of manganese and iron ions from an albic soil (Albic-Udic Luvisol), a yellow-red soil (Hap-Udic Ferrisol) and a yellow-brown soil (Arp-Udic Luvisol) induced by calcium salt addition and their bioavailability to pepper (Capsicum frutescens L.) were studied in a pot experiment. Addition of Ca(NO3)2 decreased soil pH and increased both exchangeable and DTPA (diethylenetriamine pentaacetic acid)-extractable Mn and Fe in soils. Meanwhile, total Mn accumulation in the shoots of Capsicum frutescens L. on the salt-treated soils increased significantly (P ＜ 0.01) compared with the control, suggesting that salt addition to soil induced Mn toxicity in Capsicum frutescens L. Although exchangeable and DTPA-extractable Fe increased also in the salt-treated soils, Fe uptake by the shoots of Capsicum frutescens L. decreased. The effect of added salts in soils on dry matter weight of pepper varied with the soil characteristics, showing different buffer capacities of the soils for salt toxicity in an order of yellow-brown soil ＞ albic soil ＞ yellow-red soil. Fe/Mn ratio in shoots of Capsicum frutescens L. decreased with increasing salt addition for all the soils, which was ascribed to the antagonistic effect of Mn on Fe accumulation. The ratio of Fe/Mn in the tissue was a better indicator of the appearance of Mn toxicity symptoms than Mn concentration alone.

Molecular cloning and functional analysis of the pepper resistance gene Me3 to root-knot nematode

Root-knot nematodes(RKNs)cause severe diseases in peppers annually around the world.In pepper,the Me3 gene provides a heat-stable and broad-spectrum resistance to RKNs.In this study,several simple sequence repeat(SSR)markers and insertion/deletion(In Del)markers were developed to fine map the Me3 gene.Analysis of 2272 individuals(F2progenies)revealed that Me3 was located in a 45-kb DNA region between markers SSR784 and SSR339,in which there were three candidate genes.Among them,as a novel nucleotide binding site and leucine rich repeat(NBS-LRR)family gene,the DNA sequence of Capana09g000163 of pepper line‘HDA149’was 6348 bp in length,with a 2802-bp open reading frame encoding 933 amino acids,including NB-ARC and LRR domains.Tobacco transient expression assays demonstrated that expression of Capana09g000163 triggered a hypersensitive response(HR)in Nicotiana benthamiana leaves.Subcellular localization results showed that the Capana09g000163 protein was localized in the cell nucleus.Ectopic expression of Capana09g000163 in Arabidopsis significantly increased resistance against Meloidogyne incognita compared with the wild-type(WT)Arabidopsis.Furthermore,M.incognita was almost unable to develop in transgenic Arabidopsis expressing Capana09g000163.Taken together,we cloned the Me3 gene and verified that it induced resistance against M.incognita with the methods of map-based cloning and transgenic technology,which may be of great significance to pepper breeding for resistance against RKNs.

AFLP Analysis of Mitochondrial DNA from a Cytoplasmic Male Sterility Line and its Maintainer in Pepper (Capsicum annuum L.)

Cytoplasmic male sterility (CMS) is a maternally inherited trait characterized by the inability of a plant to produce functional pollen, which is widespread among higher plants. CMS system is a valuable tool for plant

Processing of Snack of Goat Chub Chili(Capsicum annuum L.)with Formulations of Tomato and Tomato-Marjoram

The cultivation of goat chili has potentially increased in Chile, due to different varieties of gourmet products made with it;for this reason, new industrial projects are sought to the growing volume to adapt them to the new trends in consumption habits, mainly focused on achieving an attractive meal, a fast preparation and consumption, while nutrients are provided to offer some benefits for human health. The “snacks” products that include the use of fruit satisfactorily respond to these requirements, in addition to providing marketing alternatives to the surplus of fruit exports. For this reason, the present test, consisting of the processing of snacks based on goat chub chili with the addition of tomato and marjoram, was carried out to increase the palatability and the sensorial quality of the final product. The following formulations were used: only chili (T1);chili and tomato (T2);chili, tomato and marjoram (T3). The latter one was characterized by a good flavor and aroma. A large amount of the fruit water content had been removed by drying it with forced hot air. A product without chemical preserves was obtained, with physical and chemical parameters similar to those required by similar foods existing on the market today. In sensorial terms, the formulation to which marjoram was added showed good sensorial and acceptability attributes, highlighting them from the rest of the treatments. The snack color was maintained after the dehydration process, according to panelists.

辣椒(Capsicum annuum L.)果实发育及品质相关新microRNA的鉴定与分析

MicroRNA(miRNA)是一种非编码的小RNA,在各种生物过程中起着重要的调节作用。前人研究表明,模式植物中miRNA与果实发育相关。然而,人们对辣椒(Capsicum annuum L.)果实品质及发育相关的miRNA了解尚不清楚。本研究利用二代测序技术(Next-generation sequencing technology)比较了不同品种辣椒果实在不同发育时期的小RNA。利用miRDeep2软件从4个样本中共鉴定出了59个已知miRNA和310个新miRNA。预测了新miRNA的靶基因,共656个,并对其中402个靶基因进行了注释。GO分析和KEGG途径表明,某些靶基因与淀粉糖、氨基糖以及核糖代谢相关。qPCR表明一些miRNA的表达模式与其靶向基因相反,该结果为今后研究miRNA调控果实发育和品质形成提供了重要基础。

Purification and Biochemical Characterization of a Protease Inhibitor Ⅱ Family from Jalapeno Pepper(Capsicum annuum L.)

Capsicum annuum L. was initially domesticated in Mexico and northern Central America, and represented an ancient Neotropical plant food complex. The purpose of this paper is to report the isolation and purification of a novo-member of a protease inhibitor from jalape&ntildeo pepper (Capsicum annuum L.) (PIJP). The molecular weight of PIJP inhibitor is 5.95 kDa with 56 amino acids and 6 Cys residues with high inhibitory activity to trypsin with a Ki value of 95 nM. This inhibitor according to the alignment with homologous from NCBI and Pfam databases is a member of proteinase inhibitors II. It is worthwhile to mention a major compositional difference between the proteinase inhibitor II families which have 8 Cys residues. PIJP is the first purified proteinase inhibitor, member of this family with only 6 Cys residues.

氰氨化钙对连作辣椒根际土壤环境及植株生长发育的影响

以加工型辣椒品种艳椒425为试材,采用大棚栽培方式,研究了氰氨化钙(CaCN_(2))不同施用量(0.3、0.6、0.9、1.2、1.5 t·hm^(-2))对连作辣椒根际土壤环境及植株生长发育的影响。结果表明:CaCN2施用量为1.2 t·hm^(-2)和1.5 t·hm^(-2)时,连作辣椒根际的土壤孔隙度、饱和含水量、田间持水量、饱和导水率等土壤物理性质及碱解氮、有效磷、速效钾和有机质等土壤养分含量均显著高于不施用CaCN2的CK,且保持了较高的土壤脲酶活性,土壤容重则比CK显著降低;辣椒结果盛期辣椒株高、开展度、单株结果数、果长及小区产量等两处理差异不显著,但均显著高于CK。随着CaCN_(2)施用量的增加,辣椒病害得到有效控制,CaCN_(2)施用量为1.2 t·hm^(-2)和1.5 t·hm^(-2)时,病株率分别仅为8.6%和5.5%,显著低于CK和其他处理。综上,CaCN2施用量为1.2 t·hm^(-2)和1.5 t·hm^(-2)能有效降低连作辣椒的病株率,显著改善根际土壤环境,并对辣椒生长发育有良好的促进作用。综合考虑应用效果及生产成本,推荐CaCN2施用量1.2 t·hm^(-2)用于缓解辣椒连作障碍。

杀虫芽孢杆菌HZ179的鉴定及其相关生物学功能研究

为明确杀虫芽孢杆菌HZ179菌株的分类地位及相关生物学功能,用形态学、生理生化特性及16S rDNA和gyrB序列分析对HZ179进行种属鉴定,通过盆栽试验,测定HZ179对辣椒幼苗生长指数、防御酶活性及单宁含量的影响;通过诊断PCR方法测定HZ179对瓜蚜共生菌的影响。结果表明,HZ179为贝莱斯芽孢杆菌(Bacillus velezensis)。HZ179能显著促进辣椒幼苗生长,其中100倍稀释液处理的幼苗株高、茎粗、植株干重、根冠比、壮苗指数与对照相比分别提高44.19%、15.70%、22.47%、16.18%和16.71%。HZ179灌根能显著提高辣椒叶片中超氧化物歧化酶(SOD)、过氧化物酶(POD)、多酚氧化酶(PPO)、苯丙氨酸解氨酶(PAL)等酶的活性及单宁含量,并在14 d内保持较高水平。HZ179处理组瓜蚜共生菌的感染种类和感染率均低于对照。贝莱斯芽孢杆菌HZ179具有促进辣椒幼苗生长、诱导产生系统抗性和抑制瓜蚜共生菌等功能。