Factors Controlling Meristematic Activity in Excised Roots IV. Habituation of the Main Axis Meristem of Excised Tomato Roots to Repeated Subculture

1953 ◽  
Vol 6 (4) ◽  
pp. 707-722 ◽  
Author(s):  
H. E. Street ◽  
Moira P. McGonagle
Keyword(s):  
Main Axis ◽  
Tomato Roots ◽  
Meristematic Activity ◽  
Repeated Subculture

THE GROWTH CURVE AND GROWTH CORRELATIONS OF EXCISED TOMATO ROOTS GROWN IN STERILE CULTURE

1965 ◽  
Vol 43 (2) ◽  
pp. 287-304 ◽  
Author(s):  
William G. Boll
Keyword(s):  
Apical Meristem ◽  
Lateral Roots ◽  
Main Axis ◽  
Naval Research ◽  
Lag Phase ◽  
Naphthaleneacetic Acid ◽  
Sterile Culture ◽  
Office Of Naval Research ◽  
Tomato Roots ◽  
Growth Correlations

The curve of growth in length of the main axis of excised tomato roots, grown in a 6-day passage, shows a 'lag phase' at the beginning and a decrease in growth rate toward the end of the passage when growth of the apex is inhibited by the older tissues. The 'lag phase' is neither due to transfer of the excised tip to fresh medium nor a consequence of the developmental stage at which the tip is excised. The 'lag phase' may mean that the apical meristem requires substances supplied by the older tissues, but it is, at least in part, due to injurious effects of excision.From surgical experiments it is concluded that the growth of lateral roots is promoted by the presence of older tissues and inhibited by the main apex and younger parts of the main axis. A comparison is made between this latter effect and apical dominance in shoots.Growth of the main axis was increased by 2,4-dichloroanisole (DCA). Growth of the lateral roots was inhibited at concentrations of 3-indolylacetic acid (IAA) and DCA which did not affect growth of the main axis. This effect was not observed with 1-naphthaleneacetic acid (NAA). At concentrations which did not affect growth of the main axis, only NAA promoted the formation of lateral roots. The evidence is reviewed that the growth correlations in the root involve 'auxin-type' growth regulators but that different regulators may be involved in the different growth correlations.The author acknowledges the loan of apparatus from the U.S. Office of Naval Research.

PEMANFAATAN RUANG PUBLIK SEBAGAI WADAH TRANSAKSI KULINER PADA LURUNG KAMPUNG PAJEKSAN – JOGONEGARAN, YOGYAKARTA

2017 ◽  
Vol 10 (5) ◽  
pp. 301
Author(s):  
Septi Kurniawati Nurhadi
Keyword(s):  
Public Space ◽  
Central City ◽  
Main Axis ◽  
The People ◽  
Usage Patterns

Abstract : Pajeksan and Jogonegaran kampongs are located in central city of Yogyakarta, while the lurung Pajeksan – Jogonegaran kampongs is the border as well as the main axis for the people living that are currently evolving as the houses for workers in the Malioboro area. The beneficial usage of the lurung has grown as the fulfillment of the people’s need for food. The usage is increasing and posing an intervention on the lurung space. This research is aimed to discover the use and the influence of culinary transaction space, culinary activity and form of element transaction space in the community of lurung Pajeksan - Jogonegaran kampongs. This is done by using the Behavior mapping. The result of identifying and analyzing is use to obtain the special characteristic that happen in the society so that they are able to keep their existence. The usage patterns of public space as the culinary transaction space in lurung Pajeksan - Jogonegaran kampongs is linier and it follows the shape of an elongated lurung with the greatest usage occurs at the junction of the driveway towards the kampongs. The usage of the lurung is directly related to the aspect of environment, neighborhood, and economic aspectKeyword : Lurung Pajeksan – Jogonegaran,The Usage of Lurung, and Culinary Transaction Space Abstrak: Kampung Pajeksan dan Jogonegaran merupakan dua kampung yang terletak di pusat kota Yogyakarta, sedangkan lurung kampung Pajeksan – Jogonegaran merupakan batas sekaligus menjadi poros utama kehidupan warga yang saat ini kampung tersebut berkembang sebagai hunian bagi pekerja di kawasan Malioboro. Pemanfaatan lurung berkembang sebagai pemenuhan kebutuhan pangan warga kampung. Pemanfaatan tersebut kian meningkat dan menimbulkan intervensi ruang pada badan lurung. Penelitian ini bertujuan untuk mengetahui pemanfaatan dan pengaruh wadah transaksi kuliner, aktivitas kuliner serta elemen pembentuk wadah transaksi yang dilakukan masyarakat pada lurung kampung Pajeksan–Jogonegaran. Hal tersebut dilakukan dengan menggunakan metode Behavior mapping. Hasil identifikasi dan analisis tersebut digunakan untuk memperoleh kekhasan yang terjadi dalam masyarakat sehingga dapat mempertahankan keberlangsungannya. Pola pemanfaatan ruang publik sebagai wadah transaksi kuliner yang terdapat pada lurung kampung Pajeksan – Jogonegaran berbentuk linier memanjang yang mengikuti bentuk lurung dengan pemanfaatan terbesar terjadi pada persimpangan menuju jalan masuk kampung. Pemanfaatan tersebut tidak terlepas dari aspek lingkungan,ketetanggaan,dan ekonomi.Kata Kunci: Lurung kampung Pajeksan - Jogonegaran, Pemanfaatan lurung, dan Wadah Transaksi Kuliner.

The LARGE2-APO1/APO2 regulatory module controls panicle size and grain number in rice

2021 ◽  
Author(s):  
Luojiang Huang ◽  
Kai Hua ◽  
Ran Xu ◽  
Dali Zeng ◽  
Ruci Wang ◽  
...  
Keyword(s):  
Agronomic Traits ◽  
Loss Of Function ◽  
Grain Number ◽  
Hect Domain ◽  
Regulatory Module ◽  
Promising Target ◽  
Meristematic Activity ◽  
Positive Regulators ◽  
Genetic Mechanisms ◽  
Biochemical Analyses

Abstract Panicle size and grain number are important agronomic traits and influence grain yield in rice (Oryza sativa), but the molecular and genetic mechanisms underlying panicle size and grain number control remain largely unknown in crops. Here we report that LARGE2 encodes a HECT-domain E3 ubiquitin ligase OsUPL2 and regulates panicle size and grain number in rice. The loss of function large2 mutants produce large panicles with increased grain number, wide grains and leaves, and thick culms. LARGE2 regulates panicle size and grain number by repressing meristematic activity. LARGE2 is highly expressed in young panicles and grains. Biochemical analyses show that LARGE2 physically associates with ABERRANT PANICLE ORGANIZATION1 (APO1) and APO2, two positive regulators of panicle size and grain number, and modulates their stabilities. Genetic analyses support that LARGE2 functions with APO1 and APO2 in a common pathway to regulate panicle size and grain number. These findings reveal a novel genetic and molecular mechanism of the LARGE2-APO1/APO2 module-mediated control of panicle size and grain number in rice, suggesting that this module is a promising target for improving panicle size and grain number in crops.

The Crystallographic Modeling of C60 Orientations in a Cubic Lattice

1994 ◽  
Vol 359 ◽  
Author(s):  
Veniamin Sh. Shekhtman ◽  
Ruben A. Dilanyan ◽  
Oksana G. Rybchenko
Keyword(s):  
Main Axis ◽  
Cubic Lattice ◽  
Orientational Glass ◽  
Orientational Ordering ◽  
Different Levels

ABSTRACTThe symmetry conditions which rule the matching of a fulleren molecule's main axis in a translational lattice are considered. The full set of orientational states for the structure of fullerene are obtained. The different levels of correlations between symmetry axes of icosahedral molecule and cubic lattice are considered. This result used for analysis of orientational ordering models, including modulation structure and discrete orientational glass.

Allelopathy: a possible mechanism of suppression of plant-parasitic nematodes by entomopathogenic nematodes

Nematology ◽  
1999 ◽  
Vol 1 (7) ◽  
pp. 735-743 ◽  
Author(s):  
Parwinder S. Grewal ◽  
Edwin E. Lewis ◽  
Sudha Venkatachari
Keyword(s):  
Meloidogyne Incognita ◽  
Entomopathogenic Nematodes ◽  
Galleria Mellonella ◽  
Steinernema Feltiae ◽  
Symbiotic Bacteria ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Tomato Roots ◽  
Xenorhabdus Nematophilus ◽  
Plant Parasitic

Abstract A possible mechanism of suppression of a plant-parasitic nematode Meloidogyne incognita by entomopathogenic nematodes is described. Heat-killed entomopathogenic nematodes Steinernema feltiae and S. riobrave temporarily suppressed penetration of the root-knot nematode M. incognita into tomato roots, but live nematodes had no effect. Infective juvenile M. incognita were repelled from all entomopathogenic nematode treatments that included their symbiotic bacteria. They were repelled by Galleria mellonella cadavers infected with S. carpocapsae, S. feltiae, and S. riobrave and from cell-free culture filtrates of the symbiotic bacteria Xenorhabdus nematophilus, X. bovienii, and Xenorhabdus sp. "R" from the three nematode species, respectively. Cell-free filtrates from all three Xenorhabdus spp. were toxic to M. incognita infective juveniles causing 98-100% mortality at 15% concentration. Cell-free filtrate of Xenorhabdus sp. "R" also reduced the hatch of M. incognita eggs. Application of formulated bacterial cell-free filtrates temporarily suppressed M. incognita penetration into tomato roots in a greenhouse trial. The short-term effects of cell-free bacterial filtrates, namely toxicity and repellency, were almost entirely due to ammonium. These results demonstrate allelopathic interactions between plant-parasitic nematodes, entomopathogenic nematodes and their symbiotic bacteria. The likely role of allelopathy in the suppression of plant-parasitic nematodes by innundative applications of entomopathogenic nematodes is discussed. Allelopathie: Ein moglicher Mechanismus zur Unterdruckung pflanzenparasitarer Nematoden durch insektenpathogene Nematoden - Es wird ein moglicher Mechanismus zur Unterdruckung des pflanzenparasitaren Nematoden Meloidogyne incognita durch insektenpathogene Nematoden beschrieben. Durch Hitze abgetotete insektenpathogene Nematoden Steinernema feltiae und S. riobrave underdruckten das Eindringen des Wurzelgallenalchens M. incognita in Tomatenwurzeln, lebende Nematoden hatten keine Wirkung. Infektionsjuvenile von M. incognita wurden von allen Behandlungen mit insektenpathogenen Nematoden abgestossen, die auch die symbiontischen Bakterien einschlossen. Sie wurden durch die Kadaver von Galleria mellonella abgestossen, die mit S. carpocapsae, S. feltiae und S. riobrave infiziert waren sowie durch zellfreie Kultursubstrate der symbiontischen Bakterien Xenorhabdus nematophilus, X. bovienii und Xenorhabdus sp. "R" aus den drei genannten Nematodenarten. Zellfreie Kultursubstrate von allen drei Xenorhabdus spp. waren giftig fur die Infektionsjuvenilen von M. incognita und verursachten in einer Konzentration von 15% Abtotungsraten von 98-100%. Zellfreie Kultursubstrate von Xenorhabdus sp. "R" vermiderten ausserdem das Schlupfen von M. incognita-Eiern. In einem Gewachshausversuch unterdruckten formulierte zellfreie Bakterienfiltrate vorubergehend das Eindringen von M. incognita in Tomatenwurzeln. Die Kurzzeitwirkungen von zellfreien Bakterien filtraten, namentlich Giftigkeit und Abstossung, waren nahezu ganz bedingt durch Ammoniak. Diese Ergebnisse zeigen das Vorhandensein von allelopathischen Wechselwirkungen zwischen pflanzenparasitaren Nematoden, insektenpathogenen Nematoden und deren symbiontischen Bakterien. Die wahrscheinliche Rolle von Allelopathie bei der Unterdruckung pflanzenparasitarer Nematoden durch eine Massenanwendung insektenpathogener Nematoden wird diskutiert.

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