Oelmüller R, Mohr H. Carotenoid composition in milo (Sorghum vulgare) shoots as affected by phytochrome and chlorophyll.
PLANTA 1985;
164:390-395. [PMID:
24249609 DOI:
10.1007/bf00402951]
[Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/1984] [Accepted: 12/19/1984] [Indexed: 06/02/2023]
Abstract
The composition of coloured carotenoids in the milo shoot was investigated quantitatively (high performance liquid chromatography) during light-mediated plastidogenesis, including the time span of 'photodelay' as caused by medium and high light fluxes. It was found that as long as only the far-red-absorbing form of phytochrome operates, the carotenoid pattern remains virtually the same as in complete darkness (violaxanthin and lutein as major constituents, traces of β-carotene). On the other hand, the pattern changes dramatically in white or red light with increasing amounts of chlorophyll (lutein and β-carotene dominate, β-carotene showing the strongest relative increase). Photodelay during the early phase of plastidogenesis affects the carotenoid composition strongly. Increase of neoxanthin, violaxanthin and β-carotene contents are diminished while lutein accumulation proves resistant towards chlorophyll-mediated photoinhibition. The photodelay can be diminished by an appropriate light pretreatment. The data indicate that light-mediated control over carotenoid accumulation is exerted at three levels: i) a coarse control through phytochrome, ii) fine tuning in connection with chlorophyll accumulation, iii) stabilization of holocomplexes against photodecomposition.
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