Über ein neues Auxin („Hetero-auxin“) aus Harn. 11. Mitteilung über pflanzliche Wachstumsstoffe

Reactive oxygen species tune root tropic responses

“…The transmitted signal in phototropism and gravitropism was later found to be a phytohormone, and its redistribution on opposite sides of the root or shoot was hypothesized to promote differential growth and bending of the organ (Went, 1926;Cholodny, 1927). Over the years, the phytohormone was characterized as indole-3-acetic acid (IAA, auxin;Kögl et al, 1934;Thimann, 1935), and the 'Cholodny-Went' theory was demonstrated for gravitropism and phototropism (Rashotte et al, 2000;Friml et al, 2002). In addition to auxin, second messengers such as Ca 2+ , pH oscillations, reactive oxygen species (ROS) and abscisic acid (ABA) were shown to play an essential role in gravitropism (Young and Evans, 1994;Fasano et al, 2001;Joo et al, 2001;Ponce et al, 2008).…”

Plant Growth Regulators

“…The following auxins are of significance as growth regulators. [87-51-4], C 10 H 9 NO 2 , M r 175.2, was isolated from human urine by Kögl in 1934 [20].…”

In memoriam Professor Corwin Hansch: birth pangs of QSAR before 1961

“…Beginning of the structure-activity study of plant growth hormones at Pomona college: formulation of two-point attachment hypothesis for substituted phenoxyacetic acids After indole-3-acetic acid (IAA) was identified to be the natural plant hormone to regulate the plant growth in 1934 [1], a number of analogous aromatic carboxylic acids were synthesized and tested. In 1941, 2-methyl-4-chlorophenoxyacetic acid (2-Me-4-Cl-POA: MCPA) and 2,4-Cl 2 -POA (2,4-D), both being markedly active as the growth hormone, were found to be highly active as selective herbicides to eradicate broad leaf weeds while protecting grass crops by W. G. Templeman and W. A. Sexton at ICI in the UK (now a part of Syngenta) [2].…”