Formation of short‐wavelength chlorophyll(ide) after brief irradiation is correlated with the occurrence of protochlorophyll(ide)_636–642 in dark‐grown epi‐ and hypocotyls of bean (Phaseolus vulgaris)

Abstract

Chlorophyll formation capacity along the seedling of bean (Phaseolus vulgaris L. cv. Brede zonder draad) was investigated. After 7 days of irradiation a gradient was formed, where the primary leaf contained ca 300 times more chlorophyll per gram fresh weight than the lower hypocotyl section and ca 20 times more than the epicotyl. Similar chlorophyll gradients but at lower levels were seen when the seedlings were first placed in darkness for 7 days and then irradiated for 1, 2 or 7 days. Ultrastructural investigation of seedlings grown for 7 days in darkness and then irradiated for 24 h revealed a more developed inner membrane system with grana stacks in plastids of cells in the uppermost hypocotyl section compared to plastids of cells in lower hypocoty] sections. The higher up on the seedling the more the ratio increased of protochlorophyll(ide) emitting at 657 nm to short‐wavelength protochlorophyll(ide). After flash irradiation of the different sections, fluorescence emission spectra with maxima at 680 and 690 nm, respectively, were observed, indicating the formation of short‐ and long wavelength chlorophyll(ide) forms. The lower the ratio of protochlorophyll(ide) emitting at 657 nm to the short‐wavelength protochlorophyll(ide), the less long‐wavelength chlorophyll(ide) was formed after irradiation. However, after continuous irradiation long‐wavelength chlorophyll(ide) was formed. In dark grown roots, where only short‐wavelength protochlorophyll forms were present, it was not possible to transform protochlorophyll to chlorophyll by flash irradiation. Possible explanations for this phenomenon are discussed.

Light and temperature regulation of greening in dark‐grown ginkgo (Ginkgo biloba)

“…At low PFD (15 μmol m −2 s −1 ) ginkgo stems were greening slowly and accumulated considerable amounts of Chl during 72 h (Table 2), similarly to the stems of etiolated angiosperm seedlings, which contain similar ratios of the different Pchlide spectral forms (Böddi et al 1996, McEwen et al 1996, Skribanek and Böddi 2001). After 24 h illumination, low amounts of non‐photoactive Pchlide forms with emission maximum at 632 and 650 nm were observed.…”

“…This way the greening of the leaves is faster then that of the stems, in which the short‐wavelength, non‐enzyme bound, monomeric forms of Pchlide are predominant (Böddi et al 1994, 1998, 2004, McEwen et al 1994, Seyedi et al 2001, Skribanek and Böddi 2001, Skribanek et al 2000, Terry et al 2001, Virgin 1996, Virgin and Sundqvist 1992). The etioplasts of the stems have small PLBs and their greening is slow (Böddi et al 1996, 2005, McEwen et al 1996, Seyedi et al 2001, Skribanek and Böddi 2001, Virgin 1993, 1996). Similar slow greening was found in very young leaves of germinating bean (Schoefs et al 1998).…”

Plastid differentiation and chlorophyll biosynthesis in different leaf layers of white cabbage (Brassica oleracea cv. capitata)

“…4A and B) and the fluorescence band of the NADP + ‐Pchlide‐containing complexes appeared at 650 nm (Franck et al 1999). The simultaneous appearance of Chlide 676 monomers and the Chlide 690 complexes is characteristic for irradiated young leaves (Ogawa et al 1978, Klockare and Virgin 1983, Schoefs and Franck 1993, McEwen et al 1996). Re‐darkening of the samples resulted in the regeneration of the photoactive NADPH–Pchlide–POR complexes (Fig.…”

The cytokinin 2‐isopentenyladenine causes partial reversion to skotomorphogenesis and induces formation of prolamellar bodies and protochlorophyllide657 in the lip1 mutant of pea

“…Fluorescence emission spectra were measured at 77 K using an SLM Aminco 8100C spectrofluorometer as described before (McEwen et al 1996). For measuring the phytochrome fluorescence emission, the lower epicotyl parts of dark‐grown wild‐type and lip 1 mutant plants were used.…”