THE ROLE OF AUXIN IN THE DIFFERENTIATION OF ROOT AND SHOOT PRIMORDIA FROM ROOT CUTTINGS OF TARAXACUM AND CICHORIUM
THE ROLE OF AUXIN IN THE DIFFERENTIATION OF ROOT AND SHOOT PRIMORDIA FROM ROOT CUTTINGS OF TARAXACUM AND CICHORIUM
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生长素在蒲公英和菊苣切根根和芽原基分化中的作用
DOI：
10.1002/j.1537-2197.1950.tb12194.x
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发表时间：
1950
影响因子：
3
通讯作者：
G. Warmke
中科院分区：
文献类型：
--
作者：
H. E. Warmke;G. Warmke
分化的问题--即具有许多特化器官、组织和细胞的成熟有机体是如何从一个受精卵发育而来的--长期以来一直是生物学家的难题。遗传学家尤其受到了挑战;在孟德尔定律和基因的基础上，他遇到了一个悖论，即试图解释一个有机体细胞的差异，而有机体的所有细胞核都有相同的染色体和基因互补。蒲公英属和菊苣属的某些乳汁混合物为Wiesner（1892）、Goebel（1902，1905，1908）、Kiister（1903）、Nemec（1908，1924，1928）和许多其他人对再生和分化的重要早期研究提供了材料。这些植物的肉质主根具有非凡的再生能力。这些可以被切成一厘米或更长的片段，在1-2周的时间内，带有莲座状叶的茎分生组织将从近端切面上形成的愈伤组织中分化出来;愈伤组织，有时是根，将在较低的表面上发育，或远端。在任何一个单一的切口，一个根段的远端和下一个根段的近端，作为一个单一切口的两个面，必须在所有方面都非常相似。然而，当把它们放在有盖容器中的湿滤纸上几天后，这两个表面的行为却截然不同;一个表面的细胞产生芽原基和小叶，而另一个表面的细胞产生愈伤组织和根（图la、B）。看来切割扰乱了根的生理统一性，并引起某些物质的重新分配，这反过来又影响了在两个切割表面上形成的愈伤组织的分化方向。Czaja早期的重要作品（1931，1935），Fischnich 03 The Dog（1938）（1940，1941），霍华德（1938年，1940年），普罗科菲耶夫（1944年），以及高特雷及其同事（1946年）最近的工作强烈地表明，根的固有极性是物质重新分配的原因，很有可能这种物质就是生长素这是目前工作的目的（1），实验改变浓度的生长素在两端的根段，以确定是否1接收出版1949年8月16日。在本调查的主要部分，作者是波多黎各大学热带农业研究所的工作人员。2最近指出了一些值得注意的例外（Huskins，1947，1948; Huskins和Steinitz，1948）。因此，可以改变分化的方向，和（2）在正常再生过程中测定未处理的片段的近端和远端切割表面的生长素，以确定是否可以检测到两端生长素浓度的差异。这项工作的初步报告已经完成（Warmke和Warmke，1946，1947）。影响改变生长素浓度.材料和方法.一株蒲公英（Taraxacum ofilicinale Weber）和一株菊苣（Cichorium Intybus L.）的根。（类似选择），增加植物性，直到大约
THE PROBLEM of differentiation-of how the mature organism, with its scores of specialized organs, tissues, and cells, develops from a single fertilized egg-has long been a nettling perplexity to the biologist. The geneticist, particularly, has been challenged; on the basis of Mendelian laws and genes, he has been confronted with the paradox of trying to account for the differences in cells of an organism, all of whose nuclei have identical2 complements of chromosomes and genes. Certain of the milky-juiced composites of the genera Taraxacum and Cichorium have provided material for such important early researches on regeneration and differentiation as those of Wiesner (1892), Goebel (1902, 1905, 1908), Kiister (1903), Nemec (1908, 1924, 1928), and many others. The fleshy tap-roots of these plants possess remarkable powers of regeneration. These may be cut into segments a centimeter or more in length and, within a period of 1-2 weeks, shoot meristems with their rosettes of leaves will differentiate from callus tissue formed on the proximal cut surfaces; callus, and sometimes roots, will develop on the surfaces of the lower, or distal, ends. At the moment any single cut is made, the distal end of one root segment and the proximal end of the next below-being the two faces of a single incision-must be very similar in all respects. Yet, when allowed to lie on moist filter paper in a covered vessel for several days, the behavior of these two surfaces is strikingly different; the cells of one produce a shoot primordium and leaflets, while those of the other produce callus tissue and roots (fig. la,b). It would appear that cutting disturbs the physiological unity of the root and causes a redistribution of some substance or substances, which in turn influences the direction of differentiation of the callus tissues formed on the two cut surfaces. The important earlier works of Czaja (1931, 1935), Fischnich (1938, 1939), Plant (1940, 1941), Howard (1938, 1940), Prokofiev (1944), and the recent work of Gautheret and his co-workers (1946) suggest strongly that the inherent polarity of the root is responsible for the redistribution of the substance, and most likely, that this substance is auxin. It was the purpose of the present work (1) to experimentally alter the concentration of auxin at the two ends of root segments, to determine if the 1 Received for publication August 16, 1949. The authors were members of the staff of the Institute of Tropical Agriculture of the University of Puerto Rico during the major portion of this investigation. 2 Some notable exceptions have been pointed out recently (Huskins, 1947, 1948; Huskins and Steinitz, 1948). direction of differentiation could thus be altered, and (2) to assay the proximal and distal cut surfaces of untreated segments for auxin during normal regeneration to determine if differences in auxin concentration at the two ends could be detected. A preliminary report of this work has already been made (Warmke and Warmke, 1946, 1947). EFFECT OF ALTERING AUXIN CONCENTRATIONS.Materials and methods.-Roots of a single plant of dandelion, Taraxacum oflicinale Weber (selected for strong regenerative capacity), and of one of chicory, Cichorium Intybus L. (similarly selected), were increased vegetatively until approximately