Untitled

Abstract

Knowledge of the genes in gymnosperms encoding the apoproteins of the plant photoreceptor phytochrome is currently scanty as for gymnosperm nuclear protein coding sequences in general. Here we report two complete cDNA-derived sequences which code for two different types of gymnosperm phytochrome. One sequence stems from Norway spruce (Picea abies) and the other from Scots pine (Pinus sylvestris). More detailed studies have shown that both types of phytochrome gene are present in Norway spruce. From phylogenetic analyses, these types appear to branch off from progenitors that are also the common ancestors of the angiosperm PHYA/PHYC and PHYB/PHYD/PHYE lineages. Partial phytochrome sequences of other gymnosperms cluster with either the one type or the other of the gymnosperm phytochrome genes characterized here. Southern blot analysis of Picea DNA using probes derived from the full-length Picea gene indicated a family of at least five members. Whether they code for new types may be doubted since only two phylogenetic clusters were found. Studies using RNA-PCR of Picea RNA extracted from either light- or dark-grown seedlings indicated that the steady-state levels of the transcripts of two PHYA/C-related genes were hardly affected by light.

Clinal variation in PHY (PAS domain) and CRY (CCT domain)—Signs of local adaptation to light quality in Norway spruce

“…The phylogenetic analysis of phytochromes is in accordance with the previous work in this area (Clapham et al, 1999; Garcia‐Gil, 2008; Mathews, 2006, 2010; Mathews, Clements, et al, 2010). The phylogenetic tree of phytochromes (Supporting Information: Figure ) shows that there are three PHYs (PHYP, PHYN and PHYO) in Norway spruce as described earlier.…”

Transcriptome analysis of shade avoidance and shade tolerance in conifers

“…Whereas a lack of correspondence between the expression level and protein activity may be the case in PHYP2/B, it is interesting to mention that PHYN/A gene expression was previously shown to remain steady in dark-and light-grown spruce seedlings (Clapham et al 1999). This apparent lack of induced PHYA expression in response to shade could be related to the absence of FR high irradiance response (FR-HIR) (known to be regulated by phyA) previously described in several conifer species including pine and Ginkgo (Fernbach and Mohr 1990; Mathews and Tremonte 2012) or presence of mild FR-HIR in Scots pine (Razzak et al 2017).…”

Clock genes and diurnal transcriptome dynamics in summer and winter in the gymnosperm Japanese cedar (Cryptomeria japonica(L.f.) D.Don)

“…Lhcb and psb A (photosystem II subunit A) mRNA levels show only small diurnal fluctuations under light/dark cycles and no circadian rhythm under continuous light or dark conditions in Douglas fir ( Pseudotsuga menziesii ) [ 65 ]. By analyzing dark-grown seedlings, expression of Lhcb genes has been shown to occur in darkness in various conifer species [ 64 - 69 ]. Expression of PHYA/C-related genes in dark-grown P. abies seedlings has also been reported [ 69 ].…”

“…By analyzing dark-grown seedlings, expression of Lhcb genes has been shown to occur in darkness in various conifer species [ 64 - 69 ]. Expression of PHYA/C-related genes in dark-grown P. abies seedlings has also been reported [ 69 ]. The mechanisms of regulation of these light-related genes in conifers might be different from those in angiosperms.…”