Phylogenetic relationships in the tribe Millettieae and allies in the subfamily Papilionoideae (Leguminosae) were reconstructed from chloroplast trnK/matK sequences. Sixty‐two accessions representing 57 traditionally recognized genera of Papilionoideae were sampled, including 27 samples from Millettieae. Phylogenies were constructed using maximum parsimony and are well resolved and supported by high bootstrap values. A well‐supported “core Millettieae” clade is recognized, comprising the four large genera Millettia, Lonchocarpus, Derris, and Tephrosia. Several other small genera of Millettieae are not in the core Millettieae clade. Platycyamus is grouped with Phaseoleae (in part). Ostryocarpus, Austrosteenisia, and Dalbergiella are neither in the core Millettieae or Phaseoleae clade. These taxa, along with core Millettieae and Phaseoleae, form a monophyletic sister group to Indigofereae. Cyclolobium and Poecilanthe are close to Brongniartieae. Callerya and Wisteria belong to a large clade that includes all the legumes that lack the inverted repeat in their chloroplast genome, which confirms previous rbcL and phytochrome gene family phylogenies. The evolutionary history of four characters was examined in Millettieae and allies: the presence of canavanine, inflorescence types, the dehiscence of pods, and the presence of winged pods. trnK/matK sequence analysis suggests that the presence of a pseudoraceme or pseudopanicle and the accumulation of nonprotein amino acids are phylogenetically informative for Millettieae and allies with only a few exceptions.
Summary: We surveyed differential gene expression patterns during early photomorphogenesis in both wild‐type and mutant Arabidopsis defective in HY5, an influential positive regulator of the responses of gene expression to a light stimulus, to identify light‐responsive genes whose expression was HY5 dependent. These gene‐expression data identified light‐regulated zinc finger protein 1 (LZF1), a gene encoding a previously uncharacterized C2C2‐CO B‐box transcriptional regulator. HY5 has positive trans‐activating activity toward LZF1 and binding affinity to LZF1 promoter in vivo. HY5 is needed but not sufficient for the induction of LZF1 expression. Anthocyanin content is significantly diminished in lzf1 under far red, which is the most efficient light for the induction of LZF1. The expression of PAP1/MYB75 is elevated in plants overexpressing LZF1, which leads to the hyperaccumulation of anthocyanin in transgenic Arabidopsis. The transition from etioplast to chloroplast and the accumulation of chlorophyll were notably compromised in the lzf1 mutant. We provide molecular evidence that LZF1 influences chloroplast biogenesis and function via regulating genes encoding chloroplast proteins. In the absence of HY5, mutation of LZF1 leads to further reduced light sensitivity for light‐regulated inhibition of hypocotyl elongation and anthocyanin and chlorophyll accumulation. Our data indicate that LZF1 is a positive regulator functioning in Arabidopsis de‐etiolation.
Phylogenetic relationships among 115 species representing the legume genus Astragalus and 12 related genera were inferred from an analysis of nucleotide sequenc...
Sequences of two chloroplast photosystem genes, psaA and psbB, together comprising about 3,500 bp, were obtained for all five major groups of extant seed plants and several outgroups among other vascular plants. Strongly supported, but significantly conflicting, phylogenetic signals were obtained in parsimony analyses from partitions of the data into first and second codon positions versus third positions. In the former, both genes agreed on a monophyletic gymnosperms, with Gnetales closely related to certain conifers. In the latter, Gnetales are inferred to be the sister group of all other seed plants, with gymnosperms paraphyletic. None of the data supported the modern “anthophyte hypothesis,” which places Gnetales as the sister group of flowering plants. A series of simulation studies were undertaken to examine the error rate for parsimony inference. Three kinds of errors were examined: random error, systematic bias (both properties of finite data sets), and statistical inconsistency owing to long-branch attraction (an asymptotic property). Parsimony reconstructions were extremely biased for third-position data for psbB. Regardless of the true underlying tree, a tree in which Gnetales are sister to all other seed plants was likely to be reconstructed for these data. None of the combinations of genes or partitions permits the anthophyte tree to be reconstructed with high probability. Simulations of progressively larger data sets indicate the existence of long-branch attraction (statistical inconsistency) for third-position psbB data if either the anthophyte tree or the gymnosperm tree is correct. This is also true for the anthophyte tree using either psaA third positions or psbB first and second positions. A factor contributing to bias and inconsistency is extremely short branches at the base of the seed plant radiation, coupled with extremely high rates in Gnetales and nonseed plant outgroups.