Transport of Root-Forming Hormone in Woody Cuttings

Abstract

It has been repeatedly observed since early times that if stems from some of our common woody plants are girdled, adventitious roots may be formed above the girdle. Although this regeneration phenomenon may result in part from an interruption of food transport, recent evidence indicates that the regeneration is controlled by hormones w^hich are transported in the phloem. The greater part of the experimental work on the nature and transport of these hormones in the plant has been done with Avena coleoptiles and pea (Pisum sativum) cuttings. WENT (12) demonstrated that a growth-promoting factor from Avena coleoptile tips will diffuse out of them into a layer of agar, and that decapitated coleoptiles will grow considerably faster if blocks of this agar are placed on the cut surfaces than if they are supplied with pure agar. The chemistry of this growth substance has been worked out especially by K6GL, HAAGEN SMIIT, AND ERXLEBEN (6, 7). Three different crystalline substances were isolated, which physiologically cannot be distinguished. They

Strigolactones fine-tune the root system

“…In contrast to the inhibitory role of cytokinin, auxin promotes adventitious root formation (Cooper 1936;Boerjan et al 1995;Delarue et al 1998). Auxin application was also shown to promote the expression of strigolactone synthesis genes in plant stems (Foo et al 2005;Hayward et al 2009), suggesting that auxin should reduce adventitious rooting.…”

Strigolactones Suppress Adventitious Rooting in Arabidopsis and Pea

“…The most well studied of these is auxin, which promotes both adventitious and lateral root formation (Cooper, 1936;Boerjan et al, 1995;Delarue et al, 1998;Zhao et al, 2001;Negi et al, 2010). The auxin-overproducing mutants such as superroot1 (sur1; Boerjan et al, 1995), sur2 (Delarue et al, 1998), and yucca (Zhao et al, 2001) produce more adventitious and lateral roots than the wild type.…”

Effects of fermented cow‐manure on rooting of mung bean cuttings: The role of nutrients and of abscisic acid

“…Among the plant hormones, auxins (Geneve and Heuser, 1982;Hartmann and Kester, 1983; and abscisic acid (ABA) (Chin, Meyer and Beevers, 1969;Basu, Roy, and Bose, 1970;Hartung, Brunhild, and Kummer, 1980) have the greatest promotive effects on root formation. Other factors which stimulate the rooting of cuttings are nitrogenous compounds (Doak, 1940;Van Overbeek, Gordon and Gregory, 1946), carbohydrates (Veierskov, Hansen and Andersen, 1976), a variety of auxin synergists, such as catechol and phloroglucinol (Goiter, 1961;Hess, 1968;James and Thurbon, 1981), and a non-auxin endogenous root forming stimulus (CRS) (Cooper, 1963;Haissig and Reimenschneider, 1992). Such factors are discussed by Wilson and van Staden (1990).…”