Biogenesis of petunia and carnation corolla chloroplasts: changes in the abundance of nuclear and plastid‐encoded photosynthesis‐specific gene products during flower development

Abstract

To study the biogenesis of the photosynthetic apparatus in corollas, as well as compositional differences between corolla and leaf chloroplasts, the levels of 12 nuclear‐ and plastid‐encoded thylakoid and stromal components were analyzed by western blotting using heterologous antisera. Relative levels of the thylakoid polypeptides analyzed in petunia (Petunia hybrida cv. Hit Parade Rosa) and carnation (Dianthus caryophyllus cv. White Sim) corollas increased, per unit chlorophyll, in parallel to corolla development, peaking at the mature stage in both flower types, with the exception of subunit V of the photosystem I (PSI) core complex, which continued to accumulate even after anthesis. The photosystem II (PSII) major light‐harvesting chlorophyll a/b protein accumulated in corollas to a level, per unit chlorophyll, similar to that in leaves in both petunia and carnation plants. Components of the cytochrome b6/f complex were found to accumulate to higher levels in corolla chloroplasts than in leaves. The opposite trend was found for components of the PSI core complex, as well as for the stromally located small and large subunits of ribulose‐1,5‐bisphosphate carboxylase, which accumulated in corollas to levels ca 2. 5 times lower than their respective levels in leaves. The latter subunits accumulated coordinately in corollas of both plant types during flower development. Data obtained from immunological studies were correlated with those at the mRNA level. Nothern blotting revealed that, in petunia corollas, the steady‐state transcript level of genes coding for the small subunit of ribulose‐l,5‐bisphosphate carboxylase was identical to that of genes coding for the major light‐harvesting chlorophyll a/b protein. Levels of both transcripts, as well as those of plastid‐encoded genes for the PSII reaction center's Dl and D2, were ca two‐thirds of their respective levels in leaves. In contrast, the level of transcript for the large subunit of ribulose‐1,5‐bisphosphate carboxylase was reduced 5‐fold in petunia corollas, as compared to leaves.

Flower proteome: changes in protein spectrum during the advanced stages of rose petal development

“…The transition from stage 1 to 4 is also accompanied by the accumulation of anthocyanin (Table 1; Ben-Meir et al 2002) and the disintegration of chloroplast components (Vainstein and Sharon 1993). Indeed, the level of chloroplast Clp protease (protein #71) increases in petals during the transition from stage 1 to 4.…”

Phenylpropanoid Scent Compounds in Petunia x hybrida Are Glycosylated and Accumulate in Vacuoles

“…The volumes of loaded samples from protoplasts and vacuoles were normalized so that they reflected an identical amount of cells/protoplasts. Samples were transferred to iBlot nitrocellulose membranes for western blot analyses and following incubation with skimmed milk-based blocking solution, membranes were reacted overnight at 18°C with the primary antibodies: epsilon subunit of tonoplast V-ATPase and cFBPase (Agrisera, diluted 1:200) (Dima et al, 2015 ; de Michele et al, 2016 ), PAL, diluted 1:1,000 (Howles et al, 1996 ), and LHCII, diluted 1:500 (Vainstein and Sharon, 1993 ). Following three 10-min washes in Tween–Tris buffered saline, the membranes were incubated for 1 h at room temperature in blocking buffer containing a 1:10,000 dilution of secondary goat anti-rabbit antibody coupled to horseradish peroxidase.…”

The petunia homologue of tomato gast1: transcript accumulation coincides with gibberellin-induced corolla cell elongation

“…After electrophoresis, the formaldehyde gel was briefly stained with ethidium bromide and photographed before blotting to ensure that equal amounts of RNA had been used for each sample. In some experiments the blots were re-hybridized with 32p-labeled probe for cytoplasmic 18S rRNA [20] to reconfirm that equal amounts of RNA had been used for each sample. In some experiments the blots were re-hybridized with 32p-labeled probe for cytoplasmic 18S rRNA [20] to reconfirm that equal amounts of RNA had been used for each sample.…”