植物器官脱落分子生物学研究进展

植物器官脱落(organ abscission)是自然界普遍的现象。器官脱落发生的区域叫做离区(abscission zone)。器官脱落时离区细胞的细胞间质和细胞壁发生降解,导致远端器官离开母体。离区的发育和功能行使是多种基因参与的精确而复杂的调控过程。落粒性是作物栽培和育种中的重要农艺性状,是植物器官脱落的典型形式之一。落粒性适宜的作物品系驯化是人类文明史上最重要的成就之一,但直到近年人们才对禾本科植物落粒的分子机制有了新的认识。本文重点综述拟南芥、水稻、番茄等模式植物中离区发育和器官脱落的分子生物学研究进展,并对今后的研究方向做了简要展望。     

IAA分解代谢相关酶（IAAO、POD）的研究进展

吲哚乙酸IAA参与植物体内诸多生理活动,其分解代谢相关酶吲哚乙酸氧化酶（IAAO）、过氧化物酶（POD）在IAA代谢过程中起着关键作用,二者通过调控植物体内IAA的水平来调控复杂的植物生长,该文综合总结了IAAO和POD近年来研究的相关进展,尤其是结合生物化学和分子生物学方面阐述了这两种酶在IAA代谢中的作用及其相关性。     

冷害后植物生理变化及外源物质调控研究进展

低温冷害会干扰植物生理代谢过程,如水分代谢、矿质营养、光合作用、呼吸作用以及新陈代谢。笔者查阅并引用了大量国内外关于冷害后植物生理变化及外源物质调控方面的参考文献,一方面,较全面地阐述了植物冷害后生理变化过程,详细介绍了冷害后植物细胞膜系统和光合作用生理变化机制,着重分析了冷害后植物体内酶活性、内源激素、活性氧以及渗透调节物质的变化及相关生理机制;另一方面,从冷害调控角度出发,综述了近年来植物生长调节剂和矿质养分在植物冷害调控方面研究概况,提出中国在植物冷害研究领域的未来发展方向与新趋势,进而为今后植物冷害相关研究提供理论依据。     

苯丙氨酸解氨酶与其在重要次生代谢产物调控中的作用研究进展

苯丙氨酸解氨酶（phenylanlanine ammonialyase,PAL, E.C.4.3.1.5）作为植物次生代谢特别是苯丙烷途径的关键酶,具有重要的生理意义。本文综述了PAL的存在与分布、分离纯化、酶学性质、三维结构和作用机制,并分析了苯丙氨酸解氨酶与植物重要次生代谢产物生产的关系,以期进一步丰富次生代谢产物的调控理论,为PAL在次生代谢产物生产中发挥作用提供基础数据。     

《保鲜与加工》杂志广告刊登办法

田世平，博士生导师，国家杰出青年基金获得者，并入选中国科学院“百人计划”。现任中国科学院植物研究所“果实采后生理病理学研究”领域首席研究员。主要从事果蔬产品采后生理病理学研究，包括采后果实在不同环境条件胁迫下的生理失调（褐变和冷害）和调控机制研究；控制果实采后病害的生物技术及机理研究；果实抗病性诱导及机理研究以及拮抗菌细胞凋亡及调控机制研究。     

外源钾对盐胁迫下植物生长和生理特征影响的研究进展

钾离子参与植物多个生理代谢过程,能不同程度地缓解植物受到的盐胁迫,促进植物生长发育。为了全面了解外源钾对盐胁迫下植物生长的影响,本研究归纳了盐胁迫对植物生长代谢的影响,钾在植物体内的生理作用以及外源钾对盐胁迫下植物生长生理特征的影响;分析了钾对盐胁迫下植物的生长发育、光合荧光特性、渗透物质及抗氧化酶活性、体内水分状况及离子分布的影响。针对当前钾离子缓解植物盐胁迫的分子机制及应用研究较少的问题,建议在今后的研究着重从以下两方面开展：（1）明确盐胁迫下植物体内钾离子转运机制、信号转导和相关基因的调控表达;（2）开展盐碱地肥料长期定位研究并研发可以提高植物耐盐性的新型钾肥。通过以上研究的开展,可为今后利用钾提高植物耐盐性以及盐渍土壤的改良提供解决方案。     

作物对干旱胁迫的响应机制及提高作物抗旱能力的调控措施研究进展

干旱是影响作物生长发育和产量的最主要非生物胁迫之一,在气候变化背景下,作物遭受干旱胁迫的风险越来越大。为了应对干旱,作物表现出一系列的抵御机制,包括形态特征和生理生化（抗氧化酶、渗透调节物质、内源激素）特性改变。本研究从上述2个方面总结了作物对干旱胁迫的响应机制,并对提高作物抗旱能力的调控措施进行了论述,主要包括：（1）筛选抗旱性品种,促进对深层土壤贮水的吸收利用;（2）地面覆盖,有利于降低土壤蒸发,增加土壤含水量;（3）节水灌溉技术,如微喷灌、滴灌等灌溉方式能实现少量多次灌溉,根区局部灌溉有利于调节气孔关闭,减少奢侈蒸腾,降低土壤蒸发;（4）抗蒸腾剂,在作物枝干及叶面表层形成超薄透光的保护膜,抑制作物水分过度蒸腾;（5）植物生长调节剂,调控植物生理代谢,增强抗旱性;（6）纳米肥料,改变作物生理生化反应,促进植株生长发育;（7）生物炭,有利于土壤通气保水,改善土壤的物理性质和土壤的持水能力。本研究系统地对以上7种措施提高作物抗旱能力的作用机理、应用前景及存在问题进行了论述,以期为应对干旱胁迫提供理论依据和技术参考。     

水稻株高表观遗传调控研究取得重大进展

最近,中国农业科学院作物科学研究所万建民课题组有关水稻株高表观遗传调控的研究结果被国际知名刊物《植物细胞（ThePlantCell）》期刊接受。该研究首次报道了表观遗传修饰对水稻株高和花器官发育的重要作用,揭示了DNA甲基化和组蛋白修饰之间的关联,为进一步研究表观遗传修饰对水稻生长发育的调控机制奠定了基础。     

五加科植物体细胞胚发生研究进展

为了给五加科植物体细胞胚发生体系的建立提供理论依据,推动五加科植物体细胞胚研究的开展,本研究总结了五加科植物体细胞胚发生方式、体细胞胚发生的影响因素（包括外植体类型、培养基类型、植物生长调节剂种类、渗透胁迫）、体细胞胚发生的生理生化及次生代谢的研究现状。提出今后研究重点在以下几方面：（1）进一步对五加科植物体细胞胚发生的影响因素研究。（2）利用体细胞胚发生方式对一些重要的五加科植物进行次生代谢物的提取、代谢途径基因调控等的研究。（3）对五加科体细胞胚发生机制的分子基础需进一步研究。     

甜荞产量与农艺性状和生理生化性状的灰色关联度分析

以12个甜荞品种为试验材料,采用灰色关联度分析法,对甜荞的7个农艺性状和6个生理生化性状与产量的关联度进行评价分析,探讨甜荞主要农艺性状和生理生化性状指标对产量影响的主次关系。结果表明,农艺性状与产量的关联度由大到小依次为结实率（0.8666）、单株粒数（0.8221）、株高（0.7720）、茎粗（0.7140）、千粒重（0.7004）、开花总数（0.6975）、干重（0.6243）;生理生化性状与产量的关联度由大到小依次为：叶绿素含量（0.7171）、丙二醛（MDA）含量（0.7035）、脯氨酸（Pro）含量（0.6372）、过氧化物酶（POD）活性（0.6369）、超氧化物歧化酶（SOD）活性（0.6191）和过氧化氢酶（CAT）活性（0.6028）。研究结果表明：选择结实率高、单株粒数多、叶绿素含量和MDA含量高的品种是甜荞生产中获得高产的重要途径。     

The Relationship Between Sugar-Nitrogen Ratio and Reproductive Organs Abscission in Faba Bean (Vicia Faba L.)

The changes of soluble sugar and total nitrogen content of vegetative organs in faba bean, sugar-nitrogen ratio, abscission of reproductive organs and the relationship between sugar-nitrogen ratio and abscission probability were studied using the faba bean cultivar Xichang Dabai . Plants were field grown in 1986, 1988 and 1990. The lands were separated into high yield land, middling yield land and low yield land according to grain yield at maturing stage. The soluble sugar content in vegetative organs (leaf + stem) was greatest from branching to floral initiation stages and pod-set to filling grain stages, and distinctly decreased at the onset of bloom and maturing stages. The total N content was greatest at branching stage, and gradually decreased with growth. In general, the sugar and total N contents in high yield lands were greatest, followed by that in middling yield and low yield lands. The sugar-nitrogen ratio varied depending on the soluble sugar content.
Average yield on high yield lands, middling yield land and low yield land across 3 years were 5048.77 kg/ha, 3744.01 kg/ha and 2378.22 kg/ha, respectively. The total reproductive organs abscission exceeded 90 % of total flower buds. Abscission probability averaged across 3 yield lands and 3 years were 21.6 %, 84.0 % and 32.8 % in flower buds, flowers, and pods, respectively. Node 7–12 of canopy produced more flowers, and fewer flowers and pods were produced in the upper and lower regions. Photosynthate supply has been implicated in control of abscission. Faba bean reproductive organs abscission probability increased with the sugar-nitrogen ratio of vegetative organs decreasing. It seemed that the soluble sugar content influenced significantly the shedding rate during flowering and pod-growing stages.     

Reproductive Abscission and Yield of Irrigated and Drought Stressed Cowpea

Two experiments were conducted under field conditions to evaluate reproductive abscission, seed yield and yield components of three cowpea [Vigna unguiculata (L.) Walp.] genotypes. In the first experiment, level of abscission and yield of two cultivars, California Blackeye Pea No. 5 (CA-5) and Speckle Purple Hull (SPH), and one experimental line (AZ-54) were studied. In the second experiment, effect of drought stress on abscission at three nodal positions, seed yield, and yield components of CA-5 were studied. Abscission in both experiments was determined by counting scars left by dropprd reproductive structures including floral buds, open flowers, and immature pods. Abscission of CA-5 and AZ-54 in the first experiment ranged between 68 and 76 % while that of SPH ranged between 86 and 89 %. CA-5 and AZ-54 retained two to three pods per peduncle, and SPH retained only one mature pod per peduncle. Average seed yields of SPH and AZ-54, respectively, were 45 and 50 % of CA-5. Drought stress in the second experiment did not affect production of floral buds Peduncle^?1 (average of 10) but significantly increased percent reproductive abscission and decreased pod retention of CA-5. Abscission in the bottom two-third nodes increased from 82 % in well-irrigated plants to 93 % in non-irrigated plants. This increase in abscission corresponded to nearly 60 % reduction in pod retention. The number of pods per peduncle in the bottom two-third nodes decreased from 1.9 in well-irrigated plants to only. 77 in non-irrigated plants. The increase in abscission and decrease in pod retention with increasing intensity of drought was greatest in the bottom one-third nodes. Drought stress did not affect abscission and pod retention in the top one-third nodes. Stress also decreased peduncles plant^?1, seeds pod^?1, and dry matter and seed yield plant^?1 but did not affect seed weight and harvest index. The decrease in seed yield was largely due to reductions in pods plant^?1 and seeds pod^?1. The reduction in the number of pods and, therefore, seed yield due to stress was because of reductions in the number of peduncles plant^?1 and increases in reproductive abscission. It is concluded external conditions that increase abscission beyond that of normal occurrence affect seed yield adversely.     

Natural variation in fruit abscission-related traits in apple (Malus)

Abscission or retention of ripening fruit is a major component of seed dispersal strategies and also has important implications for horticultural production. Abscission-related traits have generally not been targeted in breeding efforts, and their genetic bases remain mostly unknown. We evaluated 144 Malus accessions representing wild species, domestic cultivars, and hybrids for abscission-related traits. We found that seasonal timing of fruit abscission in wild species and hybrids showed a broad distribution similar to that seen for domestic cultivars, and that internal ethylene concentration at the time of abscission varied by over three orders of magnitude. Wild species, domestic cultivars, and hybrids all included representatives that showed abscission of fruit prior to substantial production of ethylene, as well as accessions that retained fruit for a significant period of time following ethylene production. For all accessions that retained fruit, fruit removal resulted in abscission of the pedicel, and exogenous ethylene promoted abscission, suggesting that the abscission zone was functional. Our results suggest important roles for mechanisms independent of fruit ethylene production in abscission.     

减库对大豆叶片碳代谢的影响

植物的碳代谢过程与植株生长和产量形成密切相关,是受源库关系影响最明显的生理过程之一。研究减库对大豆叶片碳代谢的影响,可为明确源库关系失衡导致的减产机理研究提供理论依据。以早熟大豆品种苏豆13为材料,于2019年和2020年在江苏省农业科学院大豆试验站进行池栽试验,在大豆R4期设置减库处理(去除全部豆荚、去掉1/2豆荚和全部种子损伤处理),以正常植株为对照,研究减库对大豆碳代谢的影响。结果表明,减库处理延缓了叶片衰老和脱落,导致叶片持绿。减库处理显著抑制了短期内的净光合速率(Pn),但是未影响初始羧化速率(a)。Pn降低主要受气孔限制,随时间延长,光合抑制作用逐渐减弱并转为促进作用,在生育后期,减库处理的叶片仍能保持相对较高的a、蔗糖磷酸合成酶(SPS)、蔗糖合成酶(SuSy)和酸性转化酶(SAI)活性及光合色素、可溶性糖、淀粉、蔗糖和果糖含量,利于维持相对较高的光合性能。减库处理导致更多的光合产物向营养器官分配,茎、叶片和叶柄在一定程度上成为新的库器官,利于生育后期的叶片光合产物输出并保持相对较高的碳代谢水平。去除全部豆荚和种子损伤处理延缓叶片衰老和脱落、光合性能和碳代谢水平降低的作用...     

高纯度卅烷醇减少棉铃脱落的效应及其生理基础

使用0.1ppm 浓度的高纯度三十烷醇溶液,以喷雾处理棉株的生殖器官—蕾、幼铃观察到下列效应:加速棉花大蕾的开花速度; 减少蕾的脱落及幼铃的脱落率,棉铃的脱落率一般可降低20%左右;延缓不受精幼铃的脱落。分析测定的结果表明:卅烷醇处理导致脱落率降低的物质基础是光合—磷酸化促进;三磷酸腺苷(能量)的贮存;干物质积累的加强     

A method for evaluating fruit abscission potential of grapes and cherry tomato clusters

Abscission is an important postharvest factor for table grapes and cluster cherry tomatoes. There are methods to measure the individual fruit removal force but until now there has been no objective method to study the abscission at a whole cluster level. The working principle of the instrument is that a cluster is attached to a rod which is allowed to fall freely for a pre-determined distance; as the rod stops, the momentum of the berries is converted to detachment force applied to the abscission zone of each berry. The abscission potential can be evaluated as a percentage of fruit detached from cluster under given conditions. The instrument was constructed for robust and adjustable experimental use. It is shown that the abscission percentage for both table grapes and cluster cherry tomatoes was proportional to the free-fall distance. By using the instrument, we showed that the abscission potential of cluster cherry tomatoes was low during the first 2 weeks of storage and that it increased thereafter. Storage of cluster cherry tomatoes at 7 °C resulted in significantly less abscission than at 12 °C, as assessed either by manual shaking or by using the instrument. Treatment of grapes with the cytokinin-like compound forchlorfenthuron at 4 mg L⁻¹ during the early stages of fruit development resulted in significant reduction in abscission potential. These results demonstrate that the method can be used as a reliable experimental tool for objective evaluation of abscission potential.     

DTA-6对大豆花荚脱落纤维素酶和GmAC基因表达的调控

叶面喷施生长调节剂(PGRs)可以调控大豆花荚脱落。2012-2013年在大庆林甸县黑龙江八一农垦大学试验基地采用大田小区试验,R1期对大豆绥农28(SN28)、垦丰16 (KF16)和合丰50 (HF50)分别叶面喷施DTA-6调节剂,对调控花荚离区脱落纤维素酶(GmAC)基因相对表达量、荚脱落纤维素酶(AC)活性、花荚脱落率和产量进行了研究。结果表明：DTA-6抑制大豆花荚离区GmAC基因相对表达量,最大可达51% (±CK%);大豆荚的AC活性能够在喷药后阶段性地被降低,在不同品种上增加和降低存在差异;能够显著降低花荚脱落率(P<0.05);能够显著增加产量(P<0.05)。植物生长调节剂DTA-6是通过降低花荚离区GmAC基因相对表达量,调节AC活性,从而减少植株的花荚脱落率,以实现对产量的调控。     

植物硫化氢生理效应及机制研究进展

硫化氢是继一氧化氮和一氧化碳之后的第三种气体信号分子。最近研究表明硫化氢在植物生长过程中起到非常重要的生理作用。本文总结了硫化氢在植物体内合成途径、硫化氢的生理效应及机制的研究进展,包括调节植物气孔关闭、种子萌发、根系发育、抗干旱、重金属胁迫、耐热激、植物抗病、植物衰老等多种生理过程,提出了利用现代生物技术进一步明确植物硫化氢信号功能及调控机制的建议。     

水稻根系形态生理及其与稻米品质关系的研究进展

水稻根系是吸收水分和养分的重要器官,也是合成和分泌植物激素、有机酸等物质的重要场所。根系形态和生理对水稻产量和品质形成有重要影响。本文综述了水稻根系主要形态生理指标及其与稻米品质的关系,并提出了未来加强水稻根系形态生理与稻米品质关系的研究方向,以期为水稻高产优质栽培根系调控提供理论依据。