scholarly journals The Abolition of the Lag Phase in Greening Cucumber Cotyledons by Exogenous δ-Aminolevulinic Acid

1974 ◽  
Vol 53 (4) ◽  
pp. 615-618 ◽  
Author(s):  
Paul A. Castelfranco ◽  
Petrovia M. Rich ◽  
Samuel I. Beale
Keyword(s):  
Aminolevulinic Acid ◽  
Lag Phase ◽  
Cucumber Cotyledons

Benzyladenine as a regulator of chlorophyll synthesis in cucumber cotyledons

1971 ◽  
Vol 49 (12) ◽  
pp. 2197-2201 ◽  
Author(s):  
R. A. Fletcher ◽  
Dianne McCullagh
Keyword(s):  
Aminolevulinic Acid ◽  
Chlorophyll Biosynthesis ◽  
Chlorophyll Synthesis ◽  
Lag Phase ◽  
Rna And Protein Synthesis ◽  
Chlorophyll Production ◽  
Cucumber Cotyledons ◽  
Ala Synthetase ◽  
Rate Limiting ◽  
Chlorophyll Formation

Pretreatment of etiolated cucumber cotyledons (4–10 days old) with benzyladenine (BA) increased the amount of chlorophyll produced in light. BA also eliminated the lag phase in chlorophyll formation, which in the water controls lasted for [Formula: see text]. Addition of δ-aminolevulinic acid (ALA) to the etiolated cotyledons resulted in the production of protochlorophyllide (PCHLD) in the dark. The BA-pretreated cotyledons did not make any PCHLD in the dark. The inhibitors of RNA and protein synthesis, actinomycin D, chloramphenicol, and cycloheximide (CH), inhibited BA's effect on chlorophyll production, with CH being the most effective. We propose that BA's effect on increased chlorophyll formation is mediated by inducing production of proteins including ALA synthetase, the rate-limiting enzyme in chlorophyll biosynthesis.

Stimulation of chlorophyll synthesis in cucumber cotyledons by benzyladenine

1973 ◽  
Vol 51 (5) ◽  
pp. 937-939 ◽  
Author(s):  
R. A. Fletcher ◽  
C. Teo ◽  
A. Ali
Keyword(s):  
Total Synthesis ◽  
Aminolevulinic Acid ◽  
Chlorophyll Biosynthesis ◽  
Chlorophyll Synthesis ◽  
Lag Phase ◽  
Cucumber Cotyledons ◽  
Ala Synthetase ◽  
Rate Limiting ◽  
Chlorophyll Formation ◽  
Stimulation Of

When exposed to light, etiolated cucumber cotyledons exhibited a lag phase in chlorophyll biosynthesis. Pretreatment of the cotyledons with benzyladenine (BA) eliminated the lag phase and stimulated chlorophyll formation. In BA-treated cotyledons, the incorporation of 14C-leucine into protein and the total synthesis of protein were higher than in the non-BA-treated controls. After BA treatment and exposure to light, the accumulation of δ-aminolevulinic acid in the cotyledons increased with time and was higher than in the controls, where a lag phase was apparent. These results support our hypothesis that BA affects chlorophyll formation by inducing the production of proteins including ALA-synthetase, the rate-limiting enzyme in chlorophyll biosynthesis.

scholarly journals No effect of plant growth retarding compounds and growth stimulators on indolo-3-acetic acid oxidase activity in greening cucumber cotyledons

2015 ◽  
Vol 42 (3) ◽  
pp. 441-452 ◽  
Author(s):  
J. S. Knypl
Keyword(s):  
Oxidase Activity ◽  
Chlorophyll Synthesis ◽  
Lag Phase ◽  
Acid Oxidase ◽  
Iaa Oxidase ◽  
Crude Enzyme Extract ◽  
Chlorophyll Accumulation ◽  
Cucumber Cotyledons ◽  
Amo 1618 ◽  
Molecular Sieving

Cotyledons dissected from 5-day-old etiolated cucumber seedlings were incubated in solutions on AMO-1618, B-Nine, CCC and Phosfon D for 48 h in light. In some tests the retardants were applied in mixed solutions with GA<sub>3</sub> or BAP. IAA oxidase was extracted and purified by means of molecular sieving through a bed of Sephadex G-25. The retardants inhibited chlorophyll synthesis by 50 % or more, and had essentially no effect on IAA oxidase activity per cotyledon basis. GA<sub>3</sub> and BAP also had no effect on enzyme activity in spite of a fact that the compounds stimulated growth of the cotyledons. The crude enzyme extract from B-Nine treated cotyledons showed lower IAA oxidase activity in comparison with the water treated control, the effect being due to a longer lag-phase preceding the initiation of IAA oxidation. KNO<sub>3</sub> strikingly stimulated expansional growth of the cotyledons, the effect being correlated with the accelerated chlorophyll accumulation. KNO<sub>3</sub> had no effect on IAA oxidase activity per cotyledon and decreased it per gram fr wt. It is concluded that [1] the growth rate of cucumber cotyledons is not correlated with IAA oxidase activity, and ;[2] the growth retarding compounds do not affect IAA oxidase system is this tissue.

Importance of RNA synthesis whthin the lag phase preceding benzyladenine-induced growth of cucumber cotyledons in the dark

1980 ◽  
Vol 21 (8) ◽  
pp. 1419-1430 ◽  
Author(s):  
K. Naito ◽  
K. Ikeda ◽  
T. Saito ◽  
H. Suzuki ◽  
M. Yamada ◽  
...  
Keyword(s):  
Rna Synthesis ◽  
Lag Phase ◽  
Cucumber Cotyledons
Sign in / Sign up

Export Citation Format

Share Document