高温胁迫对黑穗醋栗幼苗光合特性的影响

以黑穗醋栗品种94-4-13和黑丰1年生扦插苗为试材,测定不同时间、不同温度(25、35、42℃)处理下叶片光合作用和荧光参数的变化,探讨高温胁迫对黑穗醋栗幼苗叶片光合机构的影响,以期为黑穗醋栗的优质生产和丰产栽培技术提供理论依据.结果表明,25℃对黑穗醋栗生长没有明显影响,35、42℃高温对黑穗醋栗生长均造成一定伤害,35℃能通过自身的调节适应高温胁迫,而42℃对黑穗醋栗产生严重影响,导致光合作用和蒸腾作用不可逆下降.黑丰在42℃处理下1~5 d内,Pn下降原因是非气孔因素占主导地位,5 d后则是气孔因素占主导地位,而94-4-13则正好相反.黑穗醋栗叶片的Fv/Fm对高温胁迫反映并不敏感.高温胁迫明显降低黑穗醋栗叶片的光合电子传递量子效率ETR和光化学淬灭系数qP,而提高非光化学淬灭系数NPQ.高温胁迫对黑穗醋栗光合机构的伤害程度与伤害部位均存在明显的剂量效应.     

高温胁迫对一品红光合作用与叶绿素荧光的影响

以一品红威望为试验材料,研究45和50℃高温处理0～2 h对一品红叶片光合作用及叶绿素荧光参数的影响.结果表明:2种高温处理0.5 h时,一品红叶片的净光合速率(P_n)均大幅下降,但此后45℃处理的P_n缓慢回升,而50℃处理的P_n则不断下降,最终为负值;叶绿素荧光参数的变化表明,45℃高温处理导致一品红叶片光系统Ⅱ(PSⅡ)反应中心失活,可能为部分可逆失活,而50℃高温处理导致的PSⅡ反应中心失活可能为不可逆失活.说明一品红对高温有较强的耐受性,45℃短期高温对其伤害是可逆的,但50℃以上的高温会对其造成不可逆的伤害.高温胁迫初期,一品红叶片能够以热的形式耗散过剩的光能,这可能是一品红在高温逆境下的一种自我保护机制.     

低温胁迫对西瓜幼苗光合作用与叶绿素荧光特性的影响

以西瓜品种早佳8424为试材,分别在中度低温(15℃/10℃)和重度低温(10℃/5℃)下进行处理,研究不同程度低温胁迫对西瓜幼苗光合作用和叶绿素荧光特性的影响。结果表明：(1）（低温胁迫下,叶绿素）a+b（含量,净光合速率Pn）,蒸腾速率（Tr）,气孔导度（Gs）均逐步下降（低温胁迫越重）光合参数下降幅度越大。在重度低温胁迫6d后其Pn降至1.56。相比处理前下降85.9%,表明重度低温已严重损害叶片光合机构极大抑制了光合作用。（2）中度低温下胞间CO2浓度(Ci)降低,与Pn、Gs变化趋势一致,故气孔限制是导致其光合速率降低的主要因素;而重度低温胁迫下Ci呈现相反上升趋势,表明其光合速率降低是由非气孔限制因素导致。低温处理均增加了叶绿素a/b,可能是西瓜幼苗对光照下低温胁迫的一种自我保护机制,因为相对少量叶绿素b能避免过多吸收光能而导致光抑制。（3）低温胁迫降低了叶片PS域最大光化学效率（Fv/Fm）和光化学淬灭系数（qP）,重度低温下非光化学淬灭系数（qN）随之下降,而中度低温下qN则表现为升高,表明中度低温胁迫下西瓜幼苗能通过叶黄素循环的热耗散途径来消除天线色素捕获的过多光能以减轻对PS域的伤害,而重度低温胁迫下幼苗的这种光保护机制已丧失,其对叶片的光合机构将造成不可逆的伤害。     

滴灌水肥一体化下施钾量对宁夏春玉米叶绿素荧光特性与产量的影响

通过2018—2019年田间试验,研究不同施钾量对宁夏春玉米叶绿素荧光特性及产量的影响.以天赐19号为试验材料,采用随机区组试验设计,设6个梯度钾肥量处理,K0(0 kg·hm-2)、K1(60 kg·hm-2)、K2(120 kg·hm-2)、K3(180 kg·hm-2)、K4(240 kg·hm-2)、K5(30...     

Dynamic changes of root proteome reveal diverse responsive proteins in maize subjected to cadmium stress

Toxic symptoms and tolerance mechanisms of heavy metal in maize are well documented. However, limited information is available regarding the changes in the proteome of maize seedling roots in response to cadmium(Cd) stress. Here, we employed an i TRAQ-based quantitative proteomic approach to characterize the dynamic alterations in the root proteome during early developmental in maize seedling. We conducted our proteomic experiments in three-day seedling subjected to Cd stress, using roots in four time points. We identified a total of 733, 307, 499, and 576 differentially abundant proteins after 12, 24, 48, or 72 h of treatment, respectively. These proteins displayed different functions, such as ribosomal synthesis, reactive oxygen species homeostasis, cell wall organization, cellular metabolism, and carbohydrate and energy metabolism. Of the 166 and 177 proteins with higher and lower abundance identified in at least two time points, 14 were common for three time points. We selected nine proteins to verify their expression using quantitative real-time PCR. Proteins involved in the ribosome pathway were especially responsive to Cd stress. Functional characterization of the proteins and the pathways identified in this study could help our understanding of the complicated molecular mechanism involved in Cd stress responses and create a list of candidate gene responsible for Cd tolerance in maize seeding roots.     

高温胁迫对西洋杜鹃光合作用和叶绿素荧光动力学参数的影响

以西洋杜鹃铁红、粉红、梅红、普红4个品种(系)的扦插苗为试验材料,分别在38℃/28℃和43℃/32℃(昼/夜)胁迫4 d后转入25℃/22℃(昼/夜)恢复,研究不同高温对西洋杜鹃光合作用和叶绿素荧光动力学参数的影响.结果表明:高温加重了光合作用光抑制,4个品种(系)的净光合速率(Pn)都下降,气孔导度随着处理时间的延长均显著下降;胞间二氧化碳浓度随着处理时间的延长均显著升高;蒸腾速率随着处理时间的延长则表现出先升高后下降的趋势.非气孔因素是导致西洋杜鹃光合作用下降的主要因素.4个品种(系)之间对高温胁迫的反应存在差异.铁红受高温的影响相对较小,Pn在4个品种(系)中的下降幅度最小;而普红Pn的变化受高温的影响最大.在叶绿素荧光动力学参数方面,高温胁迫4 d后,4个品种(系)的原初光能转换效率、光合电子传递量子效率、光化学猝灭系数和非光化学猝灭系数均显著下降.在恢复试验中,38℃组仅有少量植株存活,而43℃组则无一植株存活,表明在38和43℃胁迫下所产生的光抑制,已导致光系统Ⅱ结构在短期内受到了不可恢复的伤害或失活.     

盆栽对柑橘叶片光合和叶绿素荧光特性的影响

以杂柑类品种‘天草’为试验材料,研究大田栽培下及不同体积盆栽限根条件下柑橘的光合特性和叶绿素荧光特性。结果表明,在不同光强下大盆栽培柑橘的净光合速率(Pn)、气孔导度(Gs)、胞间CO₂浓度(Ci)及蒸腾速率(Tr)与大田栽培相比均无显著差异;而小盆栽培显著降低了柑橘植株的Pn,Gs及Tr,但Ci无明显变化。大盆栽培会引起植株对高浓度CO₂的利用能力降低,但小盆栽培植株对不同浓度CO2的利用能力都显著低于大田栽培。从叶绿素荧光参数来看,大盆栽培除了导致天线色素转换效率(Fv'/Fm')下降以外,对PSⅡ最大光化学效率(Fv/Fm)、PSⅡ的实际光量子产量(ΦPSⅡ)、PSⅡ的电子传递速率(ETR)、光化学猝灭系数(qP)及非光化学猝灭系数(NPQ)均无显著影响;而小盆栽培导致Fv'/Fm',ΦPSⅡ,ETR显著下降,NPQ显著上升。能量分配分析的结果与光合和叶绿素荧光参数变化相一致。     

Phenotypic characterization and genetic mapping of the dwarf mutant m34 in maize

Plant height is one of the most important agronomic traits associated with yield in maize.In this study,a gibberellins(GA)-insensitive dwarf mutant,m34,was screened from inbred line Ye478 by treatment with the chemical mutagen ethylmethanesulfonate(EMS).Compared to Ye478,m34 showed a dwarf phenotype with shorter internodes,and smaller leaf length and width,but with similar leaf number.Furthermore,m34 exhibited smaller guard cells in internodes than Ye478,suggesting that smaller cells might contribute to its dwarf phenotype.Genetic analysis indicated that the m34 dwarf phenotype was controlled by a recessive nuclear gene.An F2 population derived from a cross between m34 and B73 was used for mutational gene cloning and this gene was mapped to a chromosome region between umc2189 and umc1553 in chromosome 1 bin1.10,which harbored a previously identified dwarf gene Zm VP8.Sequencing analysis showed a nucleotide substitution(G1606 to A1606)in the sixth exon of ZmVP8,which resulted in an amino acid change(E531 to K531)from Ye478 to m34.This amino acid change resulted in anα-helix changing to aβ-sheet in the secondary protein structure and the‘SPEC’domain changed to a‘BOT1NT’domain in the tertiary protein structure.Taken together,these results suggested that m34 is a novel allelic mutant originally derived from Ye478 that is useful for further ZmVP8 functional analysis in maize.     

不同光照强度对石栎幼苗叶绿素含量及叶绿素荧光参数的影响

以亚热带常绿阔叶林中的常见种石栎(Lithocarpus glaber)为研究材料,测定了不同光强条件(100%、75%和50%自然光强)下幼苗叶绿素荧光参数及叶绿素含量,探讨了石栎生长对光强的适应性。结果表明,随着光照强度的减弱,石栎叶片的叶绿素含量上升,3种光强条件下叶片光系统Ⅱ的实际光化学效率(ΦPSII)、最大光能转化效率(Fv/Fm)和潜在活性(Fv/Fo)的季节变化规律相似,高光强下的ΦPSII、Fv/Fm和Fv/Fo值相对较小,说明石栎幼苗能适应较大的光强幅度,同时对低、弱光强有一定的抗逆性。     

Irrigation mitigates the heat impacts on photosynthesis during grain filling in maize

Elevating soil water content (SWC) through irrigation was one of the simple mitigation measures to improve crop resilience to heat stress. The response of leaf function, such as photosynthetic capacity based on chlorophyll fluorescence during the mitigation, has received limited attention, especially in field conditions. A two-year field experiment with three treatments (control treatment (CK), high-temperature treatment (H), and high-temperature together with elevating SWC treatment (HW)) was carried out during grain filling with two maize hybrids at a typical station in North China Plain. Averagely, the net photosynthetic rate (P_n) was improved by 20%, and the canopy temperature decreased by 1–3°C in HW compared with in H in both years. Furthermore, the higher SWC in HW significantly improved the actual photosynthetic rate (Phi2), linear electron flow (LEF), variable fluorescence (F_v), and the maximal potential quantum efficiency (F_v/F_m) for both hybrids. Meanwhile, different responses in chlorophyll fluorescence between hybrids were also observed. The higher SWC in HW significantly improved thylakoid proton conductivity (gH⁺) and the maximal fluorescence (F_m) for the hybrid ZD958. For the hybrid XY335, the proton conductivity of chloroplast ATP synthase (vH⁺) and the minimal fluorescence (F_o) was increased by the SWC. The structural equation model (SEM) further showed that SWC had significantly positive relationships with P_n, LEF, and F_v/F_m. The elevating SWC alleviated heat stress with the delayed leaf senescence to prolong the effective period of photosynthesis and enhanced leaf photosynthetic capacity by improving Phi2, LEF, F_v, and F_v/F_m. This research demonstrates that elevating SWC through enhancing leaf photosynthesis during grain filling would be an important mitigation strategy for adapting to the warming climate in maize production.     

3个台湾青枣品种与野生毛叶枣光合作用及叶绿素荧光特性的比较

对高低两种光强(200、800 μmol/m2·s)下3个台湾青枣品种(蜜丝、五千和大脆蜜)与野生毛叶枣的光合作用和叶绿素荧光特性的比较研究结果表明,两种光强下大脆蜜的光合速率和水分利用效率都显著高于蜜丝和五千,甚至达到了野生毛叶枣的水平;五千耐荫能力最强,大脆蜜最差.建议根据几个台湾青枣品种的不同光合、蒸腾、水分利用和叶绿素荧光特性,并结合果园的光照和水分条件选择适宜的品种.     

干旱胁迫对6种藤本植物光合作用及叶绿素荧光参数的影响

为筛选出抗旱性强的藤本植物,以络石、常春油麻藤、扶芳藤、常春藤、金银花、绿爬山虎6种藤本植物的一年生扦插苗为试材,研究干旱胁迫对6种藤本植物光合作用及叶绿素荧光参数的影响,比较分析6种藤本植物的抗旱性。结果表明:随着干旱胁迫的加重,叶绿素相对含量、净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、光饱和点(LSP)、光补偿点(LCP)、最大光化学效率(Fv/Fm)、电子传递速率(ETR)及光化学猝灭系数(qp)均下降,水分利用效率(WUE)及初始荧光(Fo)提高;在轻度干旱(LS,土壤含水量为田间持水量的75%~70%)下,金银花的净光合速率(Pn)高于其他5种藤本植物,常春藤的净光合速率(Pn)低于其他5种藤本植物;在重度干旱(SS,土壤含水量为田间持水量的35%~30%)下,络石的水分利用效率最高,为7.96μmol/(m2·s),绿爬山虎的水分利用效率最低,为3.82μmol/(m2·s)。从光合作用及叶绿素荧光参数等指标综合分析,抗旱性由强到弱的植物依次为络石、常春油麻藤、扶芳藤、常春藤、金银花、绿爬山虎。     

钾营养对中华猕猴桃叶片光合作用及叶绿素荧光的影响

对中华猕猴桃"81-5"品种采用4种钾水平处理.结果表明,NPK2处理可以增加猕猴桃叶绿素含量,显著提高光合速率、气孔导度和水分利用效率,降低叶绿素a/b值、叶片蒸腾速率和胞间CO2浓度.NPK2和NPK3处理可使一天中光合速率提前到达峰值,有效延缓植株的"午休".NPK1和NPK2处理能提高猕猴桃叶片的Fv/Fm和Fv/Fo,激活叶片电子传递活性和PSⅡ潜在活性、提高PSⅡ原初光能转化效率.缺钾和低钾会使叶片吸收的过剩光能通过光化学反应途径和非辐射能量途径耗散的能力降低.     

不同LED光源对设施越冬辣椒光合特性和叶绿素荧光参数的影响

采用不同LED光源照射植株,研究不同光质、不同补光时间对设施越冬辣椒光合参数及叶绿素荧光参数的影响。结果表明：不同LED光源、不同补光时间对辣椒叶片的光合速率、气孔导度、蒸腾速率、胞间CO2浓度以及叶绿素荧光参数Fv′/Fm′,qN,ΦPSⅡ,ETR,qP均有显著的影响。采用较短补光时间（6 h和8 h）,RB光和B光均能显著提高辣椒叶片的光合速率、胞间CO2浓度和ΦPSⅡ,ETR,而且补光6 h的效果好于8 h;采用较长补光时间（10 h）时,RB光能显著提高Fv′/Fm′,而W光及RB73光却耗掉更多的热能。RB83处理6 h和8 h能显著提高辣椒的光合作用,可作为设施辣椒越冬生产的补光光源。     

铅污染对茶条槭和五角槭光合作用和叶绿素荧光特性的影响

以北方阔叶树种茶条槭(Acer ginnala)和五角槭(Acer mono )1年生苗木为材料,采用土壤和风化砂混合物作为盆栽基质,设置0(CK)、100、500、1000、2000 mg/kg 5种土壤Pb2+质量浓度,研究土壤铅污染对苗木叶片光合作用和叶绿素荧光特性的影响.结果表明:总体趋势上,随着土壤Pb2+质量浓度的增加,茶条槭的光合速率(Pn)逐渐下降,蒸腾速率(Tr)、气孔导度(Gs)和胞间CO2浓度(Ci )先升后降;五角槭的光合速率先升后降,蒸腾速率和气孔导度逐渐下降,胞间CO2浓度逐渐升高;随着土壤Pb2+质量浓度的增加,两树种的原初光能转换效率(Fv/Fm)和PSⅡ的潜在活性(Fv/Fo)先升后降,光化学猝灭系数(qP)和光化学量子效率(ΦPSII)逐渐下降,非光化学猝灭系数(qN)茶条槭表现为先升后降;在土壤Pb2+质量浓度大于500 mg/kg时,茶条槭光合速率的下降是气孔限制和非气孔限制二者共同作用的结果,五角槭光合速率的下降主要由非气孔限制因素所致;两树种各叶绿素荧光参数与光合速率均无显著相关;在土壤Pb2+质量浓度低于1000 mg/kg时,铅污染对两树种生长的影响不显著,两树种均可作为目前城市中铅污染区域的绿化树种     

LED光源不同光质下葡萄试管苗增殖和叶绿素荧光动力学特征

采用LED不同波长(红+蓝、白、红、蓝、黄和绿)光源,以白色荧光为对照,研究不同光质条件下葡萄试管苗的增殖特性、光合特性和叶绿素荧光动力学特性.结果表明:葡萄试管苗的增殖倍数、冠鲜质量、根鲜质量、叶面积、叶绿素含量、净光合速率、叶绿荧光参数Fv/Fm、qP、ΦPSⅡ和Fv/Fo在LED红+蓝光下最高,而胡萝卜素含量和NPQ最低,在LED黄光和绿光下净光合速率为负值.在LED蓝光下,根长最短,这说明短波光抑制根系的伸长生长.     

NaCl胁迫对不同品种番茄幼苗生长和叶绿素荧光特性的影响

研究了NaC l胁迫(0、50、100 mmol.L-1)下番茄‘沪番2560’(耐盐性较强)和‘沪番2608’(耐盐性较弱)植株生长、叶绿素含量、叶绿素荧光特性和渗透调节物质的影响。结果表明,NaC l胁迫明显降低植株生长、叶片叶绿素含量、PSⅡ潜在活性(Fv/Fo)、光化学效率(Fv/Fm),显著增加脯氨酸和可溶性糖含量。‘沪番2560’幼苗生长受盐胁迫的影响小于‘沪番2608’,其光合机构受盐胁迫的伤害程度小于‘沪番2608’。     

NaHCO3胁迫对转TaLEA基因山新杨生长及光合、叶绿素荧光特性的影响

为了筛选耐苏打盐渍土的转基因杨树优良株系, 以苏打盐渍土的主要成分NaHCO₃胁迫处理转TaLEA基因的山新杨各株系与对照(NT),测定不同株系的苗高和地径等生长性状,测定净光合速率(P_n)、胞间CO₂浓度(C_i)、气孔导度(G_s)、蒸腾速率(T_r)等光合参数以及最大光化学效率(F_v/F_m)、光化学猝灭系数(qP)、非光化学猝灭系数(NPQ)、实际光化学电子产量(Φ_PSII)等叶绿素荧光动力学参数,利用染色法分别比较各株系的超氧离子和过氧化氢的累积情况,进而综合评价不同株系对NaHCO₃胁迫的响应。结果表明,NaHCO₃胁迫处理前、后各株系的苗高和地径生长量发生明显分化,由处理前的差异不显著,到处理20 d后的显著,转基因株系的苗高、地径普遍较对照高,表现突出的是转基因株系SL2号,其平均苗高和地径分别较对照提高了17.4%、15.7%;对照的盐害指数是转基因株系的3.3倍,并且转基因株系的平均存活率是对照的2.8倍。各转基因株系的光合参数和荧光参数也较对照增强,P_n、T_r在胁迫20 d后转基因株系较对照分别高了237.38%、649.02%,G_s、C_i在胁迫15 d时转基因株系较对照分别高了119.05%、24.56%,其中SL2号转基因株系较对照分别提高150%、25.81%。各转基因株系的F_v/F_m平均为0.68,对照只有0.45,前者的qP和Φ_PSII只略高于后者,后者的NPQ却是前者的6倍。转基因株系的超氧离子和过氧化氢累积量均少于对照。在相同的碱胁迫环境下,转基因山新杨,尤其是SL2,能保持较快的生长量、较强的光合能力和较低的ROS水平,初步选择其为耐苏打盐渍土的杨树转基因优良株系。      

GsMAPK4, a positive regulator of soybean tolerance to salinity stress

Salt stress is one of the major factors affecting plant growth and yield in soybean under saline soil condition. Despite many studies on salinity tolerance of soybean during the past few decades, the detailed signaling pathways and the signaling molecules for salinity tolerance regulation have not been clarified. In this study, a proteomic technology based on two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS) were used to identify proteins responsible for salinity tolerance in soybean plant. Real-time quantitative PCR (qRT-PCR) and Western blotting (WB) were used to verify the results of 2-DE/MS. Based on the results of 2-DE and MS, we selected glucosyltransferase (GsGT4), 4-coumarate, coenzyme A ligase (Gs4CL1), mitogen-activated protein kinase 4 (GsMAPK4), dehydration responsive element binding protein (GsDREB1), and soybean cold-regulated gene (GsSRC1) in the salinity tolerant soybean variety, and GsMAPK4 for subsequent research. We transformed soybean plants with mitogen-activated-protein kinase 4 (GsMAPK4) and screened the resulting transgenics soybean plants using PCR and WB, which confirmed the expression of GsMAPK4 in transgenic soybean. GsMAPK4-overexpressed transgenic plants showed significantly increased tolerance to salt stress, suggesting that GsMAPK4 played a pivotal role in salinity tolerance. Our research will provide new insights for better understanding the salinity tolerance regulation at molecular level.