THE SYNTHESIS OF FLOWERING HORMONE 



71 



Table 9-1. Compounds which Inhibit Flowering of Cocklebur, 



Arranged According to Their Effective Times 



OF Application 



Compound 



Concentra- 

 tion which 

 inhibits 50% 



EfTect on 

 the critical 

 dark period 



Inhibition 

 reversed by 

 metabolite 



A. Effective during time 

 measurement (Curve A, 

 Fig. 9-11). 

 Cobaltous ion 



SK & F 7997 (tris (2-diethyl- 

 aminoethyl) phosphate) 

 (Zeevaart) 



5-Fluorouracil (Zeevaart 

 and Bonner) 



Effective during second part 

 of the dark period or before 

 (Curve B, Fig. 9-11). 



1 . Respiration uncoupler, 

 2,4-Dinitrophenol 



2. Anti-amino acids 

 Ethionine 



p. Fluorophenylalanine 



3. Anti-nucleic acids 

 5-Fluorouracil (Salisbury 

 and Bonner) 

 Benzimidazole 



2,6-diaminopurine sulfate 



8-chloroxanthine 

 4. Miscellaneous Quercetin 

 C. Effective during the 

 translocation period 

 (CurveC, Fig. 9-11) 

 1. Auxins 



Indole acetic acid (lAA) 



Naphthaleneacetic acid 

 (NAA) 



3.0x10-3m 



2 mg/ml 

 1.0x10-3 



2.0x10-2 



1.0x10-2 

 2.0x10-2 



3.0x10-3 



2.0x10-2 



2.0x10-3 



.0x10-2 

 .0x10-2 



1.0x10-= 



2.0x10-* 



Extends it 



none 

 none 



None 

 Extends it 



None 

 None 

 None 



None 

 None 



None 



None 



Many compounds 

 known to chelate 

 withCo++(Ch.8) 



Orotic acid 



Methionine 

 Phenylalanine 



Orotic acid 



Orotic acid 

 and uracil 

 Sporadically with 

 orotic acid and 

 uracil, not with 

 adenosine or 

 guanine 



Slightly by 

 antiauxins 



Slightly by 

 antiauxins 



