0 引言
【研究意义】伊犁绢蒿(Seriphidium transiliense)是蒿属荒漠草地主要建群种植物之一[1-2]。如长期过度放牧,伊犁绢蒿形态发生变化,逐渐出现矮化、小型化、老化,在群落中的占有率也越来越少,甚至消失,取而代之的是角果藜(Ceratocarpus arenarius L.)和叉毛蓬(Petrosimonia sibirica (Pall.) Bunge)等一年生植物[3-4],草场质量等级大幅度降低,草场的有效利用率大大减小[5]。草地植物表型除了受植物自身基因表达以外,放牧对其有直接性影响。因此,对比分析长期自由放牧和围栏封育的伊犁绢蒿其形态特征和内源激素含量变化,分析围栏封育效果,对退化的蒿属荒漠草地生态系统中植被恢复有重要意义。【前人研究进展】重度放牧使糙隐子草(Cleistogenes squarrosa)的株高和叶长显著降低,使其茎粗显著增加[6]。随着放牧强度的增加,冰草(Agropyron cristatum)的株高和生物量降幅最大,其次是根长和根表面积[7]。在重度放牧条件下,克氏针茅(Stipa krylovii)株高变矮、叶片数和分蘖数变少、叶片变短变窄,植株基部茎粗与叶片厚度减小[8]。植物表型特征往往与植物体外源激素和内源激素也密切相关[9-10]。目前,针对外源激素对牧草产量影响的相关报道较多[11⇓-13],与之相关的内源激素报道较少[14-15]。植物内源激素是微量的、自然产生的物质,具有特异性的化学性质和结构,这些化合物通过复杂的信号转导途径调节植物生长发育,表现出控制细胞分化和增殖的网络反馈调节[16]。牧草生长发育和种子打破休眠同样受内源激素调控[17],脱落酸(ABA)可提高羊草的产量和品质[18],土壤盐碱化程度与羊草叶片生长素和赤霉素含量[19]呈显著负相关关系,与羊草叶片脱落酸含量呈显著正相关关系[20]。种子解除休眠后,体内生长素(IAA)含量改变[21]。【本研究切入点】围栏封育是目前退化草地治理最有效、最广泛的措施之一[22],在促进植被自然更新[23]、改变草地植物群落结构[24]、提高土壤养分[25]、增加草地固碳能力[26-27]和提高生产力等占据绝对优势[28]。需研究围栏封育和自由放牧对伊犁绢蒿生长规律和内源激素水平的影响。【拟解决的关键问题】分析围栏封育(4年)和长期自由放牧(165只绵羊/hm2)的伊犁绢蒿的表型特征、叶片、茎、根系内源激素的变化特征及二者之间的相互关系,研究围栏封育对伊犁绢蒿恢复生长的影响以及各指标与内源激素的关系及围栏封育效果,为退化的蒿属荒漠草地生态系统中植被恢复研究提供理论参考依据。
1 材料与方法
1.1 材料
试验样地设置于新疆畜牧科学院草业研究所的荒漠草地固定监测站(E 86°07'19.41″,N 44°02'23.32″),海拔940~990 m,年平均气温4.7℃,最高气温35℃,最低气温-30℃左右。年降水量为240 mm,蒸发大,降雨少,无霜期163 d,主要土壤类型为栗钙土。建群种为伊犁绢蒿,伴生种为木地肤(Kochia prostrata)、叉毛蓬和角果藜等,主要用于春秋放牧利用[29]。试验地于2016年8月围栏封育。围栏封育前,放牧家畜为绵羊,放牧强度为165只羊/hm2,利用时间为每年春季和秋季各2个月,利用方式为长期放牧,伊犁绢蒿株数为5~9株/m2,株高平均13 cm,分枝数3~8个/株。自由放牧样地延续传统放牧制度,放牧强度和利用时间与围栏封育前保持一致。
1.2 方法
1.2.1 试验设计
2020年8月,伊犁绢蒿营养生长停止,逐步进入开花期。在围栏封育4年的样地内和传统自由放牧的样地内分别设置3条固定样线,每样线长200 m,每样线每隔5 m设置1个样方,监测样方内伊犁绢蒿、挖取单株、采集叶片、茎和根系样品,密封袋贴标签带回实验室。
1.2.2 指标测定
1.2.2.1 生长指标
高度(Plant height,PH):采用卷尺测量伊犁绢蒿的自然高度,每样方测量5株,每处理测量600株,求其均值;
盖度(Plant coverage,PC):采用盖度框法测定,每处理测定120次,求其均值,取整;
密度(Plant density,PD):采用现场计数法,每样方计数1次,每处理计数120次,求其均值,取整;
生物量(Biomass,B):采用现场将每样方内的伊犁绢蒿齐地面刈割后,分别装袋,带回实验室置80℃烘干至恒重,称其干重;
一级分枝(Primary branch number,PBN):由伊犁绢蒿根部萌生的分枝。采用计数法,每样方随机计数5株,每处理计数120株,求其均值,取整;
二级分枝(Secondary branch number,SBN):在一级分枝上生长的枝条为二级分枝;单株叶片、茎和根系干重等。
每样方挖取单株1株(根系挖取15×15×20 (cm3)),每处理挖取120株,分别装入密封袋带回实验室,将叶片、茎、根(根系带回后用流动水冲洗掉泥土,立即将根系)分别置80℃烘干至恒重,称其干重。
1.2.2.2 内源激素指标
(1)内源激素取样
在监测样方的同时,在固定样线上,每处理随机选取10株单株,采集其叶片、茎和根系(根系挖取15×15×20 (cm3)),将同一处理同一部位的样品混合后,分成3份,分别装入保鲜袋中,根系用流动水冲洗干净后与叶片和茎一起放入干冰中保存留用于内源激素测定。
(2)内源激素测定
测定指标包括:IAA、细胞分裂素(CTK)、赤霉素(GAs)、ABA、乙烯(ETH)。
样品提取:称取研磨好的样品100 mg,加入氧化锆珠,加入1 mL提取液(乙腈∶水=1∶1),提取液中加入少量抗氧化剂(二乙基二硫代氨基甲酸钠),冰上提取4 h,4℃条件下12 000 r/min离心10 min,取上清。
样品纯化:MAX小柱活化:依次用4 mL甲醇、2 mL 0.1 mol氨水溶液活化小柱;上样:样品经真空浓缩后,加入0.1 mol氨水溶液定容至2 mL,过MAX小柱;淋洗:依次用2 mL 0.1 mol氨水溶液,2 mL 0.1 mol氨水60%甲醇溶液淋洗;洗脱:加入0.2 mL甲醇溶解,上机。
仪器色谱参数:色谱系统采用的是Waters超高效液相系统(AcQuity UPLC,Waters, USA),根据化合物的性质,采用Waters HSS T3(50 mm×2.1 mm,1.8 μm)液相色谱柱,进样量为μL,柱温为40℃;流动相0.1%乙酸-乙腈,流动相0.1%乙酸-水。
质谱参数:质谱系统采用的是美国Thermo公司的Q exactive高分辨质谱检测系统,配有电喷雾(ESI)离子源和Xcalibur工作站。优化质谱分析条件如下:鞘气40、辅助气10、离子喷雾电压-2 800 V、温度350℃、离子传输管温度320℃。
定量结果:样品中各组分含量(ng/mg)=C×V/M,其中,C为仪器读取的浓度;V为样品提取液体积;M为样品称取总量。
1.3 数据处理
采用SPSS17.0进行数据处理,单因素方差分析采用Duncan 法多重比较两处理间的差异显著性(P<0.05或P<0.01);采用Excel2007制图。
2 结果与分析
2.1 围栏封育和自由放牧对伊犁绢蒿生长趋势的影响
研究表明,围栏封育和自由放牧条件下的伊犁绢蒿表型特征和生长趋势差异极显著(P≤0.01),围栏封育的伊犁绢蒿株高与自由放牧株高相比,提高了2.57倍,生物量是自由放牧的29.73倍,一级分枝是自由放牧的7倍,叶片干重是自由放牧的7.87倍,茎干重是自由放牧的5.21倍,根系干重是自由放牧的5.64倍。表1
表1 围栏封育和自由放牧下伊犁绢蒿生长趋势变化
Tab.1
| 项目 Items | 高度 PH (cm) | 盖度 PC (%) | 密度 PD (株/m2) | 生物量 B (g/m2) | 一级分枝 PBN (个/株) | 二级分枝 SBN (个/株) | 叶片干重 (g/株) | 茎干重 (g/株) | 根系干重 (g/株) |
|---|---|---|---|---|---|---|---|---|---|
| 围栏封育 Enclosure | 17.50±2.07 | 45±5.10 | 16±1.07 | 174.83±5.88 | 14±1.14 | 19±1.52 | 2.44±0.10 | 9.12±1.01 | 11.44±1.01 |
| 自由放牧 Free-grazing | 6.81±0.77 | ≤1±0.01 | 2±0.42 | 1.20±0.11 | 2±0.02 | 0±0.00 | 0.31±0.02 | 1.75±0.03 | 2.03±0.04 |
| 显著性(P) Significance | 0.001 | 0.000 | 0.001 | 0.000 | 0.001 | 0.000 | 0.001 | 0.001 | 0.000 |
2.2 围栏封育和自由放牧对伊犁绢蒿各器官内源激素含量的影响
研究表明,伊犁绢蒿属于多年生半灌木植物,返青早,且在每年的7月营养生长达到旺盛时期,8月各器官的形态数量指标已达到年内峰值,体内激素水平相对处于较稳定状态。围栏封育和自由放牧对伊犁绢蒿叶片生长素(IAA)、赤霉素(GAs)和乙烯(ETH)含量差异不显著,仅对细胞分裂素(CTK)和脱落酸(ABA)含量有影响,且差异显著(P<0.05%)。围栏封育和自由放牧对伊犁绢蒿茎内源激素含量影响较大,除了赤霉素(GAs)在两个处理间差异不显著以外,其他指标在两个处理间差异均极显著(P<0.01%),且IAA、CTK和ETH含量都是围栏封育处于较高水平,仅有ABA含量是自由放牧处于较高水平。围栏封育和自由放牧对伊犁绢蒿根系内源激素影响较小,仅ETH含量在二者之间差异显著(P<0.05%)。虽然IAA、ABA、GAs和CTK含量在两个处理间差异不显著,但都是围栏封育处理处于较高水平。图1~3
图1
图1
围栏封育和自由放牧下伊犁绢蒿叶片内源激素变化
注:不同小写字母表示差异显著(P<0.05),不同大写字母表示差异极显著(P<0.01)。下同
Fig.1
Effects of fencing and free grazing on endogenous hormones in leaves of Seriphidium transiliense
Note: different lowercase letters represent significant difference (P < 0.05),Different uppercase letters represent extremely significant difference (P < 0.01).The same as below
图2
图2
围栏封育和自由放牧下伊犁绢蒿茎内源激素变化
Fig.2
Effects of fencing and free grazing on endogenous hormones in stems of Seriphidium transiliense
图3
图3
围栏封育和自由放牧下伊犁绢蒿根系内源激素变化
Fig.3
Effects of fencing and free grazing on endogenous hormones in roots of Seriphidium transiliense
2.3 伊犁绢蒿内源激素含量与植株生长趋势数量指标的关系
2.3.1 叶片内源激素含量与植株生长趋势数量指标的关系
研究表明,围栏封育和自由放牧条件下,伊犁绢蒿高度、盖度、密度、生物量和二级分枝均与内源激素相关性不显著。一级分枝数与CTK含量和ABA含量密切相关,呈极显著正相关性或显著正相关性,与GAs呈显著负相关。图4
图4
图4
伊犁绢蒿叶片内源激素含量与植株生长趋势关联热图
Fig.4
Heat map of correlation between leaf blade endogenous hormone content and plant growth trend of Seriphidium transiliense
2.3.2 茎内源激素含量与植株生长趋势数量指标的关系
研究表明,围栏封育处理下伊犁绢蒿的高度与ETH和IAA含量呈极显著正相关,与GAs呈显著负相关;ABA和CTK含量与一级分枝数量呈显著正相关。自由放牧处理下伊犁绢蒿高度与内源激素指标含量相关性均不显著,一级分枝数量与ETH、ABA和CTK含量均呈显著正相关。不论是围栏封育还是自由放牧,内源激素含量均与一级分枝数量表现出强的相关性,与叶片内源激素含量与伊犁绢蒿生长趋势数量指标相关性表现出相似的规律。图5
图5
图5
伊犁绢蒿茎内源激素含量与植株生长趋势关联热图
Fig.5
Heat map of correlation between stem endogenous hormone content and plant growth trend of Seriphidium transiliense
2.3.3 根系内源激素含量与植株生长趋势数量指标的关系
研究表明,围栏封育条件下,ETH含量与株高呈极显著正相关性,GAs含量与株高呈显著负相关性,ABA 含量与一级分枝数量呈显著负相关性,CTK含量与一级分枝数量呈极显著负相关性。自由放牧条件下,仅一级分枝数量与ETH含量呈显著正相关性,ABA含量与一级分枝数量呈极显著负相关性,GAs含量与一级分枝数量呈显著负相关性。图6
图6
图6
伊犁绢蒿根系内源激素含量与植株生长趋势关联热图
Fig.6
Heat map of correlation between root endogenous hormone content and plant growth trend of Seriphidium transiliense
3 讨论
3.1
围栏封育的伊犁绢蒿一级分枝和二级分枝远多余自由放牧的伊犁绢蒿个体,围栏封育使伊犁绢蒿茎叶茂盛,向大型化生长,围栏封育对伊犁绢蒿的恢复性生长起到积极作用。自由放牧条件下的伊犁绢蒿个体低矮、分枝少、生物量低,个体矮化、小型化。荣浩等[30]对四子王旗退化荒漠草原研究结果表明,松土补播、施肥复壮、草种包衣等修复措施与围栏封育结合使用,退化草地植物恢复效果显著,且在保持水土资源,增加群落稳定性等方面效益最好。胡金娇等[31]以重度退化草地为对照,围栏封育后,草地植物盖度提高了13.5倍,生物量提高了13倍。研究结论与胡金娇的研究结论[31]相似,围栏封育和自由放牧条件下的伊犁绢蒿生长趋势差异极显著(P≤0.01),围栏封育的伊犁绢蒿株高是自由放牧株高的2.57倍,生物量是自由放牧的29.73倍,覆盖度是自由放牧的近45.0倍,一级分枝是自由放牧的7倍。
3.2
研究结果表明,围栏封育和自由放牧2个处理对伊犁绢蒿叶片、茎和根系的内源激素含量影响程度不同,从差异性分析来看,对茎内源激素含量影响更大。与自由放牧处理相比,围栏封育IAA、CTK和GAs含量在根、茎和叶中的含量均处于较高水平,围栏封育有利于伊犁绢蒿体内IAA、CTK和GAs含量的积累,IAA、CTK和GAs对伊犁绢蒿生长有促进作用,与刘泓言等[32]对草木樨幼苗生长的研究结论相似,其含量越高越有利于植株的伸长生长。一级分枝数与多个内源激素指标含量均呈现显著或极显著相关性。自由放牧条件下伊犁绢蒿被啃食后再生长,一级分枝数与围栏封育相比减少很多,且大部分分枝生长缓慢,到秋季时,自由放牧处理的伊犁绢蒿二级分枝数几乎为零,与韩召奋等[33]在反式玉米素合成基因促进烟草再生试验结论相反。围栏封育可以很好地改变伊犁绢蒿体内内源激素水平,使伊犁绢蒿形态特征、生长趋势与自由放牧的小型化和矮化形成鲜明对比。
3.3
叶片和茎内源激素各指标含量总体与伊犁绢蒿高度和一级分枝数关系较为密切,尤其是围栏封育处理,原因与围栏封育处理(消除放牧因素)有很大关系,围栏封育为伊犁绢蒿生长提供了良好环境,体内内源激素水平处于正常状态,从而参与生命体的生长、代谢、发育、繁殖、免疫及抗病虫害等方面均具有广泛的生理调节作用[34];当植物受到外界干扰胁迫时,其自身的代谢产物和生理调节物质发生变化[35],自由放牧处理的伊犁绢蒿由于受到放牧压力的影响,体内内源激素水平失调,影响植株正常生长,表现出植株矮化、长势弱。伊犁绢蒿叶片和茎的ETH、ABA和CTK含量与伊犁绢蒿一级分枝有密切关系,与自由放牧相比,围栏封育条件下的伊犁绢蒿内源激素有更多指标与植株生长趋势关系明显。
4 结论
围栏封育使伊犁绢蒿形态特征、生长趋势与自由放牧的小型化和矮化形成鲜明对比,围栏封育4年,伊犁绢蒿株高、生物量和一级分枝分别是自由放牧的2.57倍、29.73倍和7倍;围栏封育与自由放牧相比,围栏封育对伊犁绢蒿茎内源激素的影响大于对叶片和根系的影响,茎在两处理间中表现为ABA、ETH、IAA、CTK之间差异极显著,仅GAs差异不显著;围栏封育条件下的叶片、茎和根系形态特征与内源激素指标间表现出更强的关联性。围栏封育不仅可以改变伊犁绢蒿形态特征和内源激素水平,而且对形态特征和内源激素含量之间的关联性有较大影响。
参考文献
不同刈割强度下伊犁绢蒿体内可溶性糖的变化及其地上与地下营养物质的关系
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伊犁绢蒿是新疆蒿属荒漠草地常见的草地建群种之一,春季担负着家畜体膘的恢复和产羔育幼,秋季家畜要在该草地上贮存更多的能量和为繁衍下一代而进行配种。以蒿属荒漠草地为基础,以伊犁绢蒿为研究对象,结合野外定点取样,分析了伊犁绢蒿根、茎、叶中可溶性糖含量在不同刈割强度下随时间的动态变化,同时,在数据分析的基础上,明确了伊犁绢蒿秋季和春季营养物质贮存和消耗始期,并对不同刈割强度下伊犁绢蒿秋季根中可溶性糖的贮存量与来年春季植物体萌发消耗碳水化合物量之间的关联性做出判断。结果表明,根部可溶性糖含量在10月15日前后完成积累,在来年植株返青时,地下(根部)的营养物质就开始消耗,向地上运输,供植株返青和生长。C<sub>2</sub>处理不仅在秋季可溶性糖积累最高,而且在来年春季植株返青生长后在体内仍然能保持一个较高的水平,C<sub>0</sub>处理在秋季或春季植株体内可溶性糖含量在4个处理中总最低,直接影响株体越冬和次年返青。这表明不刈割并不是牧草最好的恢复方式,适度刈割有利于牧草的生长和体内可溶性糖的循环利用,但C<sub>0</sub>只能使植株处于劣势或死亡。
Temporal variation of water soluble carbohydrate in Seriphidium transiliense under different mowing intensities and it how to transfer during seasonal change
[J].<i>Seriphidium transiliense</i> is one of a common constructive species of sagebrush desert in Xinjiang, which is responsible for livestock recovery body fat, lambing, nurture young in spring pasture and storage next generation in autumn pasture. The paper analyzed the water-soluble carbohydrate dynamic change in roots, stems, and leaves of <i>S. transiliense</i> in different mowing intensities based on the sagebrush desert and field positional sampling. Meanwhile, based on the analysis for data, the beginning stage of nutrient storage and consumption of <i>S. transiliense</i> made clear, but also, the relevance was judged between water-soluble carbohydrate storage amount in autumn root and plant consumed carbohydrate for germination in coming year. The results showed that, the content of water-soluble carbohydrate in roots finished the accumulation on Oct. 15. When the plants are beginning turning green in the coming year, water-soluble carbohydrate stored in roots transferred from belowground back to aboveground automatically, which providing nutrients to turning green and regrowth. Water-soluble carbohydrate of C<sub>2</sub> treatment was different comparing to others, it not only had a highest sugar accumulation in autumn and maintained a higher content after plants turning green and regrowth in coming year, water-soluble carbohydrate content of C<sub>0</sub> treatment always the lowest one regardless of in autumn or in spring, metabolism was mild recession in plants body and maintaining its life reluctantly. Non-mowing is not the best recovery method, this explained that moderate mowing is advantageous to forage grass growth and recycling. But C<sub>0</sub> even presented inferior strength and the death.
不同利用方式下伊犁绢蒿贮藏营养物质的比较
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Comparison of Nutrition Substance Stored in Seriphidium transiliense under Different Utilization Model
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伊犁绢蒿构件动态变化研究
[J].为确定新疆蒿属荒漠草地建群种个体构件的自然生长规律,2005-2006年采用实地调查与室内分析相结合的方式,连续两年对蒿属荒漠草地建群种伊犁绢蒿(Seriphidium transiliense)个体构件数量及产量进行动态监测。结果表明:伊犁绢蒿在整个生长季内株高和枝条重量基本呈线性生长,增长速度呈"快-慢-快"的趋势;枝条数量及叶片重量分别呈"升高-降低-升高"双峰曲线形式;根重变化不明显,均在6.1g/株左右;从整体上看,伊犁绢蒿地上部分和个体总产量均呈"S"型变化;各构件在年度之间存在一定的波动性,可能与当年的水热条件相关;从利用上看,伊犁绢蒿荒漠草地适宜在4-6月、9-10月进行放牧。
Studies on Dyna mic Characteristics of Seriphidium transiliense Modules
[J].Excessive grazing and irrational grazing system had resulted in the severe degradation of sagebrush desert in Xinjiang and restricted the development of seasonal stock raising in Xinjiang. In order to understand the growth law of individual module of dominant species and guide the reasonable utilization and reversion of sagebrush desert grassland in Xinjiang, the amount and yield dynamics of individual modules of <i>Seriphidium transiliense</i> in sagebrush desert grassland was investigated in field and laboratory in 2005 and 2006. Results show: height and tiller weight of <i>S.transiliense</i> were linearly increased during entire growing season, and emerged in a ‘rapid-slow-rapid’ shape on rate of growth; the tiller quantity and leaf biomass had "increase-reduce-increase" and "double growth peaks" in curve shapes, respectively; the root biomass had no significant difference and averaged 6.1 g per individual plant; both the whole yield and aboveground biomass of S. transiliense emerged in S shape; the fluctuations of modules between 2005 and 2006 was probable related to the local conditions of moisture and temperature. Desert grassland of S. transiliense was suitable for grazing from April to June in spring and from September to October in fall during the whole growing season.
伊犁绢蒿个体功能性状对短期禁牧的可塑性响应
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Response of Short-term Grazing Exclusion to Individual Functional Traits of Seriphidium transiliense
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伊犁绢蒿荒漠群落特征及植物多样性对短期封育的响应
[J].【目的】研究封育对草地群落特征和植物多样性的影响规律,为该类退化草地恢复治理和科学经营提供理论依据。【方法】以玛纳斯县封育3a的伊犁绢蒿荒漠草地为对象,采用野外调查取样的方法,测定不同生长季(5月、7月和9月)围栏内外的群落数量特征,计算植物多样性指数。【结果】(1)与放牧区相比,伊犁绢蒿荒漠草地短期封育(3a)后群落高度、盖度和生物量分别显著提高52.55%~91.80%,40.28%~108.75%和44.36%~75.32%(PPPP>0.05)。【结论】短期封育(3a)有利于退化伊犁绢蒿荒漠草地植被的恢复,但对植物多样性影响相对较小。
Response of Community Characteristics and Plant Diversity of Seriphidium transillense Desertsto Short-term Fencing
[J].<b>【Objective】</b> This research aims to clarify the effect of short-term fencing on the community characteristics and the plant diversity, which might provide a theoretical basis for the scientific management and recovering of the degraded grassland.<b>【Method】</b>The <i>Seriphidium transilliense</i> deserts of fencing 3 years in Manas County were as research object, and the community characteristics, plant diversity indexes of the fencing plot and the grazing plot indifferent growing season (May, July and September) were measured and analyzed by using the method of sampling field survey.<b>【Result】</b>(1) Compared with grazing plot, the community height, coverage and biomass of <i>S. transilliense</i> deserts in fencing plot were significantly increased (<i>P</i><0.05) by 52.55%-91.80%, 40.28%~-108.75% and 44.36%-75.32%, respectively, while the responses of plant diversity indexes to fencing were relative low as a whole; (2) The community coverage, density, Margalef index, Shannon-Wiener index and Simpson index inside and outside the fence in May were significantly higher than in July and September (<i>P</i><0.05), and the community height were significantly lower than in July and September (<i>P</i><0.05), whereas the community biomass were not significantly different between the months (<i>P</i>>0.05).<b>【Conclusion】</b>Short-term fencing (3a) is beneficial to the restoration of vegetation in degraded<i>S. transiliense</i> deserts, but it has relative low effect on plant diversity.
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Effects of Different Grazing Intensities on Functional Traits of Cleistogenes squarrosa
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冰草地上-地下性状对放牧强度的非对称性响应
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Asymmetrical Response of Aboveground and Belowground Traits of Agropyron cristatumto Grazing Intensities
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6-苄基腺嘌呤对香云幼苗淹水胁迫下内源激素平衡的影响
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千里香叶片性状的数量分类与内源激素含量分析
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脱落酸对羊草人工草地产量及其品质的影响
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CO2 enrichment enhanced drought resistance by regulating growth, hydraulic conductivity and phytohormone contents in the root of cucumber seedlings
[J].The coordinated effects of CO enrichment and drought stress on cucumber leaves have attracted increasing research attention, but few studies have investigated the effects of CO enrichment on the root system under drought stress. So we analyzed the morphological parameters, hydraulic conductivity, aquaporin-related gene expression, and endogenous phytohormone contents in roots of cucumber seedlings cultured under different CO concentrations (approximately 400 and 800 ± 40 μmol mol) and drought stresses simulated by polyethylene glycol 6000 (0%, 5%, and 10%). The results showed that under drought stress, regardless of the CO concentration, the root biomass and hydraulic conductivity decreased, the contents of auxin (IAA), zeatin nucleoside (ZR), and gibberellin (GA) decreased, the abscisic acid (ABA) content and the transcript levels of the aquaporin-related genes CsPIP2-4 increased, and the transcript levels of the aquaporin-related genes CsPIP2-5 and CsPIP2-7 decreased compared with no drought stress. Under moderate drought stress, CO enrichment decreased ABA content and the transcript level of CsPIP2-4, increased root biomass and GA content and the transcript level of CsPIP2-7, improved contribution rate of cell-to-cell water transport (mediated by aquaporins) and roots hydraulic conductivity. In summary, drought stress changed the water transport capacity of the roots and inhibited the growth of cucumber seedlings. CO enrichment regulated phytohormone contents and aquaporin-related gene expression, maintained the normal contribution rate of cell-to-cell water transport, and improved the root biomass and hydraulic conductivity, thereby alleviated the negative effects of drought stress on cucumber seedlings.Copyright © 2020 Elsevier Masson SAS. All rights reserved.
放牧干扰对伊犁绢蒿表型性状特征的影响
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Differences of Tillering and Endogenous Hormone Content of Cunninghamia lanceolata Clones in Different Soil Depth
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五大类传统植物激素对植物响应盐胁迫的调控
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Several Kinds of Phytohormone in Plants Responses to Salt-stress
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The Effection of Brassinolide for the Drought Resistance of Chinensis
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植物激素在种子休眠与萌发中的调控机制
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Regulation of plant hormones on seed dormancy and germination
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围封对退化草地地上植被影响的综述
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A review of the effects of enclosure on aboveground vegetation in degraded grassland
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不同围封年限对典型草原群落及大针茅种群特征的影响
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Influence of Fencing Duration on Community and Population of Stipa grandis in a Typical Steppe
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短期围封对草甸草原群落特征与物种多样性的影响
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Influences of Short-term Enclosure on Characteristics of Community and Species Diversity on Meadow Steppe
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禁牧对中度退化伊犁绢蒿荒漠草地土壤养分的影响
[J].
Effects of Grazing Exclusion on Soil Nutrition in Moderate Degraded Desert Grassland ofSeriphidium transiliense
[J].
封育年限对伊犁绢蒿荒漠土壤有机氮组分的影响
[J].
Effect of Grazing Exclusion length on Soil Organic nitrogen in Seriphidium transiliense
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封育年限对蒿类荒漠土壤有机碳组分及其碳、氮特征的影响
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Effect of enclosure period on carbon and Nitrogen Characteristics and Components of Soil Organic Carbon in Artemisia desert
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中国草原管理的发展过程与趋势
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The Process and Future tend of Grassland Management in China
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荒漠草原不同植被恢复模式的水土保持生态效益
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Ecological Benefits of Soil and Water Conservation in Different Vegetation Restoration Patterns on Desert Steppe
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青藏高原东缘半湿润沙地典型生态恢复模式的效果比较研究
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Comparison study to the effectiveness of typical ecological restoration measures in semi-humid sandy land in eastern Qinghai-Tibetan Plateau,China
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农杆菌GV3101中反式玉米素合成基因促进烟草再生
[J].胭脂碱型农杆菌GV3101已经被广泛用于植物遗传转化研究。已有的研究结果证明，农杆菌GV3101株系含有的反式玉米素合成 (trans-zeatin synthesizing，tzs)基因编码产物会影响烟草细胞器的形态及细胞的生理状态。然而，有关tzs基因对遗传转化过程外植体再生的影响研究却少有报道。本文在前期研究工作的基础上，以2种烟草、4个农杆菌株系为组培实验材料，验证了胭脂碱型农杆菌tzs基因产物的生理活性。结果表明：以外源添加生长调节物质的外植体为阳性对照，在不添加任何生长调节剂的培养基上，与GV3101菌株共培养的烟草外植体能分化再生，并发育成完整植株；外植体再生与GV3101携带的质粒种类无关；外植体与农杆菌GV3101培养液共培养24 h，烟草再生效果较好；与GV3101株系共培养24 h，将外植体烟草叶片匀浆，经亲和柱分离纯化后，检测出烟草外植体叶片中高达0.78 ng/g FW-1的反式玉米素含量。菌落PCR扩增结果证实，农杆菌GV3101株系有tzs基因序列。以上结果表明，农杆菌GV3101株系内的tzs基因的表达产物有生理学活性，能够促进烟草外植体再生，调节细胞生长。
Trans-zeatin Synthesizing Gene in Agrobacterium tumefaciens GV3101Strain Stimulates the Explant Regeneration of Nicotiana
[J].Ti plasmid of nopaline type Agrobacterium contains a trans-zeatin synthesizing gene. Agrobacterium strain GV3101 is widely used in plant genetic transformation experiment. The previous studies show that Agrobacterium GV3101 strain contains tzs genes which affect the organelle morphology and physiological state of the cells of tobacco. However, there are few studies on the influence of tzs genes on the regeneration of explants. Based on the previous findings, two tobacco varieties and four strains of Agrobacterium were used as tissue cultural materials in this research to testify the biological activity of tzs gene products. The leaf explants grew on MS medium with plant growth regulator were used as positive control. The tissue culture results indicate that explants co-cultured with GV3101 strains could regenerate and reproduce integrated plant in the medium without plant growth regulators; explant regeneration is independent on the types of plasmids in GV3101; explant regeneration ratio is better when the explants were co-cultured with Agrobacterium GV3101 supernatant for 24 hours; the content of anti-tzs in the explants was 0.78 ng/g FW-1 and high level of tzs was detected in the leaves of tobacco explants after co-culture with GV3101 for 24 hours and purification of the homogenization of tobacco explants leaves by affinity column. Colony PCR amplification showed that Agrobacterium tumefaciens GV3101 strain has tzs gene sequence. These results showed that expression products of tzs gene in Agrobacterium tumefaciens GV3101 strain has physiological activity which improves cell growth and explants regeneration.
生长激素激活受体机理的研究进展
[J].生长激素(growth hormone,GH)是一种含有191个氨基酸的多肽类激素,分子质量为22 ku,由垂体前叶分泌进入血液循环,与靶细胞膜表面以二聚体形式存在的生长激素受体(growth hormone receptor,GHR)相结合。对于受体的激活来说,仅是二聚化还不够,还需在GH的诱导下发生构象变化,进而才能诱发Janus激酶2(Janus kinase 2,JAK2)的酪氨酸磷酸化,并通过4条不同的路径将信号传入细胞内,从而发挥代谢、增殖及分化等一系列生理效应。作者就生长激素与受体的结构、作用机理、信号转导通路的进展进行综述。
Research Progress on the Mechanism of Growth Hormone-activated Receptor
[J].
H2S对弱光胁迫下高羊茅幼苗生理特性和内源激素的影响
[J].为了探讨外源硫化氢（H<sub>2</sub>S）在弱光胁迫下对高羊茅（Festuca arundinacea）生理特性和内源激素的调节作用，本文以高羊茅品种Arid 3号为试验材料，在弱光胁迫下分别喷施外源H<sub>2</sub>S供体（NaHS）、H<sub>2</sub>S清除剂次牛磺酸（HT）、H<sub>2</sub>S合成酶抑制剂羧甲基胺半盐酸盐（AOA）和蒸馏水，测定其对高羊茅萌发特性、细胞膜稳定性、根活力和内源激素的影响。结果表明：弱光下施加H<sub>2</sub>S显著提高了发芽率、发芽势、活力指数、内源H<sub>2</sub>S和脱落酸（ABA）含量，同时降低了丙二醛（MDA）、细胞膜透性和超氧阴离子（O<sub>2</sub><sup>·-</sup>），且较单独遮荫处理分别降低了17.5%，23.0%和11.0%；而施加HT和AOA会抑制内源H<sub>2</sub>S的效果。综上，H<sub>2</sub>S能够提高弱光胁迫下高羊茅的ABA水平，增强萌发特性，维持细胞膜的稳定性和完整性，从而减轻弱光胁迫引起的细胞膜氧化损伤，提高高羊茅对弱光胁迫的适应能力。
Effects of H2S on Physiologica Characteristics and Endogenous Hormones in Tall Fescue Seedlings under Low-light Stress
[J].This study evaluated the effects of exogenous hydrogen sulfide (H<sub>2</sub>S) on the physiological characteristics and endogenous hormones in tall fescue (<i>Festuca arundinacea</i> schyeb. cv. ‘Arid 3’) seedlings under low-light stress. The seedlings of Arid 3 under low-light stress were sprayed with sodium hydrosulfide (NaHS, H<sub>2</sub>S donor), hypotaurine (HT, H<sub>2</sub>S scavenger), aminooxy acetic acid (AOA, H<sub>2</sub>S biosynthesis inhibitor), and distilled water respectively;and the indicators of germination characteristics, membrane stability, root vitality and endogenous hormones were determined. The results showed that exogenous H<sub>2</sub>S significantly increased the germination rate, germination potential, vitality index, endogenous H<sub>2</sub>S and abscisic acid (ABA) contents under low-light stress. Meanwhile, malondialdehyde (MDA) and superoxide anion (O<sub>2</sub><sup>·-</sup>), relative electrolyte leakage, and gibberellin (GA) levels were decreased by 17.5%, 11.0%, and 23.0%, respectively. However, the HT or AOA treatment inhibited the effects of exogenous H<sub>2</sub>S. It indicates that exogenous H<sub>2</sub>S can increase ABA level, improve germination characteristics, maintain the membrane stability and integrity under low-light stress, thereby alleviate oxidative damage and enhance the adaption to low-light stress in tall fescue seedlings.
