棉纤维分化和发育研究进展

棉纤维分化和发育研究进展邱金龙王隆华颜季琼（华东师范大学生物系,上海２０００６２）ＡＤＶＡＮＣＥＳＩＮＴＨＥＳＴＵＤＹＯＮＤＩＦＦＥＲＥＮＴＩＡＴＩＯＮＡＮＤＤＥＶＥＬＯＰＭＥＮＴＯＦＣＯＴＴＯＮＦＩＢＥＲＱｉｕＪｉｎ－ｌｏｎｇＷａｎｇＬｏｎｇ－ｈ...     

影响棉纤维分化和发育的因素

概述了棉纤维细胞分化和发育的过程,对影响棉纤雏分化和发育的因素进行了探讨,并对今后棉纤维的研究发展趋势进行了展望．     

棉纤维发育的分子生理机制

本文综述了棉纤维分化、发育的分子生理机制的研究现状,着重讨论了棉纤维细胞膨压的产生、细胞壁的松弛、结构分子的合成和加入、次生壁增厚的启始信号、纤维素的生物合成和细胞骨架系统控制纤维素沉积等机制。进而对本领域的研究前景提出了看法。     

棉纤维发育及其相关基因表达调控研究进展

棉纤维的强度和长度是评价棉花品质优劣的重要标准。棉纤维发育是一个高度程序化的调控过程。在纤维发育的各个时期,均有大量基因参与纤维细胞发育的调控。本文介绍棉纤维细胞发育各个时期的形态结构和生理生化特征以及一些纤维特异性基因表达调控等方面的研究概况和最新进展,以期能够在细胞和分子水平上了解棉纤维发育的基本生物学过程及其调控机制。     

棉纤维发育及其相关基因表达调控研究进展

棉纤维的强度和长度是评价棉花品质优劣的重要标准。棉纤维发育是一个高度程序化的调控过程。在纤维发育的各个时期, 均有大量基因参与纤维细胞发育的调控。本文介绍棉纤维细胞发育各个时期的形态结构和生理生化特征以及一些纤维特异性基因表达调控等方面的研究概况和最新进展, 以期能够在细胞和分子水平上了解棉纤维发育的基本生物学过程及其调控机制。     

棉纤维发育过程中基因表达的研究进展

棉纤维发育过程中基因表达的研究进展陈松周宝良（江苏省农业科学院经济作物研究所，南京２１００１４）吴敬音（江苏省农业科学研究院生物遗传生理研究所，南京２１００１４）前言棉纤维是由胚珠表皮细胞经过分化、伸长、次生壁加厚等一系列过程发育形成的，其发育过程...     

棉纤维发育过程中细胞壁超微结构变化的研究

应用X射线衍射法研究了棉纤维发育过程中细胞壁超微结构变化的动态规律.其结果是:次生壁S_2层的平均微纤丝螺旋角随花后生长天数的增加而逐渐变小:纤维素微晶粒间的取向度逐渐变大;花后5—14天内,结晶度缓慢增加,14—17天内陡然增加,17天后缓慢趋向最大值.     

6-BA和ABA缓解棉纤维发育低温胁迫的生理机制

以科棉1号棉花品种为材料,于2006、2007年在江苏南京(长江流域下游棉区)设置播期(4月25日、5月25日)和生长调节剂(6-BA、ABA)试验,研究低温条件下,外施6-BA、ABA对棉铃及棉纤维发育的影响及其生理机制.结果表明:常温和低温条件下,6-BA处理均能使相应部位棉铃铃质量增加、纤维品质提高;ABA处理在常温条件下会导致品质下降,而在低温逆境条件下可使纤维品质下降幅度减小;6-BA显著提高了棉铃蔗糖含量及蔗糖合成酶、蔗糖磷酸合成酶活性,而ABA则可诱导β-1,3-葡聚糖酶活性;6-BA、ABA对纤维发育关键酶蔗糖转化酶活性的作用效果均不显著.低温条件下外施6-BA、ABA均可提高棉纤维品质,但两者作用机制不尽相同:6-BA主要通过提高纤维素合成相关酶的活性,而ABA则主要通过诱导棉株抗逆性来提高纤维品质.     

激素和脂肪酸对棉花纤维发育调控的研究进展

棉花是一种重要的经济作物和油料作物,结合近几年激素和脂肪酸在棉花胚珠发育和纤维伸长过程中的重要作用,详细阐述植物激素和脂肪酸(诸如生长素、赤霉素、乙烯、油菜素内酯、超长脂肪酸、脱落酸、细胞分裂素等)在棉花纤维发育过程中的最新研究进展。     

赤霉素信号转导与棉纤维的分子发育

赤霉素(Gas)作为一种高效能的植物生长调节物质对棉纤维的分化和发育有着非常重要的影响, 但是, 一直以来有关赤霉素与棉纤维分化和发育的分子机制的研究还很少。文章论述了近年来GA信号组分、转导途径的分子生物学研究进展以及GA与棉纤维分子发育的相关研究成果, 旨在为揭示赤霉素调控棉纤维分化和发育的分子机制以及改善棉纤维品质的棉花育种工作提供新的思路。     

Ovule and suspension culture of a cotton fiber development mutant

Summary Growth and development of cotton fibers in a developmental mutant, Ligon-lintless, and its near isogenic wild type, Texas Marker-1, were compared in ovule and cell suspension cultures. In both organ and cell cultures the pattern of growth of fiber cells from the two genotypes mimicked the pattern ofin vivo growth. The timing of fiber cell initiation soon after anthesis in Ligon-lintless suggests that the fiber cells on this mutant are analogous to the commercially important lint fibers. Length distributions of elongated cells from cell suspension culture of Ligon-lintless and Texas Marker-1 indicate that the length attained in culture is affected by the genotype of the explant tissue.     

Xyloglucan breakdown during cotton fiber development

Cotton (Gossypium herbaceum L.) fibers elongated almost linearly up to about 20 days post anthesis. The molecular mass of xyloglucans in fiber cell walls decreased gradually during the elongation stage. When enzymatically active (native) cell wall preparations of fibers were autolyzed, the molecular mass of xyloglucans decreased. The decrease was most prominent in wall preparations obtained from the rapidly elongating fibers. The xyloglucan-degrading activity was recovered from the fiber cell walls with 3 mol/L NaCl, and the activity was high at the stages in which fibers elongated vigorously. These results suggest the possible involvement of xyloglucan metabolism in the regulation of cotton fiber elongation.     

Production of micronucleoli and onset of cotton fiber growth

Experiments focused on the early development of fiber cells of cotton (Gossypium hirsutum L. cv. MD51 ne) ovules produced two novel findings: one biological, the other methodological. The first concerns a micronucleolus in the nucleus of fibers. This developmental marker appears at or a little before 4 days postanthesis (dpa) in about 10% of the fibers and increases thereafter to nearly 80% provided the fibers are growing on fertilized ovules. Micronucleoli are neither seen in nuclei of fibers at 0–2 dpa nor in nuclei of non-fiber cells. Consequently, it is postulated that they are the product of specific developmental genes associated with fiber growth. The second, methodological finding, involves a cytological means of directly counting the number of fibers produced on young ovules at 1–4 dpa. The method provides quantitative data unavailable in the past. We used this method to show that emasculation caused a temporary 24-h delay in the initiation of fibers, that 30% of the fibers are affected, and that at 3 dpa both fertilized and unfertilized ovules have about 14 500 fibers. These data indicate that the fibers on fertilized and unfertilized ovules represent the same cell populations, a finding heretofore unknown. Received: 24 October 1997 / Accepted: 5 January 1998     

Changes in the level of tubulin subunits during development of cotton (Gossypium hirsutum) fiber

The levels of tubulin protein in developing cotton ( Gossypium hirsutum L. cv. Stoneville 825) fibers were measured from 8 to 28 days post-anthesis using commercially available monoclonal antibodies against alpha- and beta-tubulin. As the monoclonal antibodies against alpha- and beta-tubulin were prepared from yeast tubulin and chick brain tubulin, respectively, indirect immunofluorescence microscopy was used to establish that the two monoclonal antibodies recognized microtubule structures in cotton fibers. Western blots of electrophoretically separated proteins in crude extracts of cotton roots and fibers showed that single polypeptides with the expected apparent molecular weight for tubulin subunits were recognized by the antisera. An enzyme-linked immunosorbent assay was used to quantify tubulin levels. From 10 to 20 days post-anthesis the level of tubulin protein increases approximately three-fold. After 20 days post-anthesis, the amount of tubulin relative to total fiber protein reaches a plateau or decreases slightly. The rapid rise in tubulin is correlated with the elongation of the fiber and an increase in cellulose synthesis.     

Response of the enzymes to nitrogen applications in cotton fiber (Gossypium hirsutum L.) and their relationships with fiber strength

To investigate the response of key enzymes to nitrogen (N) rates in cotton fiber and its relationship with fiber strength, experiments were conducted in 2005 and 2006 with cotton cultivars in Nanjing. Three N rates 0, 240 and 480 kgN/hm2, signifying optimum and excessive nitrogen application levels were applied.The activities and the gene expressions of the key enzymes were affected by N, and the characteristics of cellulose accumulation and fiber strength changed as the N rate varied. Beta-1,3-glucanase activity in cotton fiber declined from 9 DPA till boll opening, and the beta-1, 3-glucanase coding gene expression also followed a unimodal curve in 12—24 DPA. In 240 kgN/hm² condition, the characteristics of enzyme activity and gene expression manner for sucrose synthase and beta-1,3-glucanase in developing cotton fiber were more favorable for forming a longer and more steady cellulose accumulation process, and for high strength fiber development.     

Factors influencing the development of cotton diseases

The observations and experiments reported in the present paper were carried out in Suinin, Szechuan Province, West China, through the period 1938-41. Under local conditions, the incidence of most cotton diseases was observed to be influenced chiefly by air humidity. No matter whether it attacks the seedlings, mature plants, or bolls, such a disease requires a humid condition preceding the occurrence of an epidemic. For sore shin disease, soil moisture and soil temperature, however, have a more profound influence. Cyrtosis, which is a disorder caused by leafhopper injury, responds to the climatic factors in a different way. During the period of rapid reproduction of the leafhopper, higher temperatures result in the earlier appearance of the disease, while heavy rainfalls reduce the intensity.
Modification of the environmental conditions by varying the time of sowing influences the incidence of diseases occurring in both the seedling and mature stages of the cotton plant. Among seedling diseases, anthracnose is further proved to be influenced chiefly by air humidity in its prevalence. Sore shin disease, on the other hand, requires a moist soil condition for its spread and development. In the mature plant, late sowing increases the intensity of cyrtosis but reduces that of bacterial blight and anthracnose.
Modification of several cultural practices was also tested. Nitrogenous fertilizers generally increase the incidence of most diseases. Denser stand and closer spacing bring about a heavier infection in stem and leaf diseases but not in boll diseases. A mixed cropping system appears to have no effect on the fungal and bacterial diseases but reduces the intensity of cyrtosis when the crop interplanted with cotton is not susceptible to the infestation of leafhopper.