The Puzzling Fate of a Lupin Chromosome Revealed by Reciprocal Oligo-FISH and BAC-FISH Mapping

Old World lupins constitute an interesting model for evolutionary research due to diversity in genome size and chromosome number, indicating evolutionary genome reorganization. It has been hypothesized that the polyploidization event which occurred in the common ancestor of the Fabaceae family was followed by a lineage-specific whole genome triplication (WGT) in the lupin clade, driving chromosome rearrangements. In this study, chromosome-specific markers were used as probes for heterologous fluorescence in situ hybridization (FISH) to identify and characterize structural chromosome changes among the smooth-seeded (Lupinus angustifolius L., Lupinus cryptanthus Shuttlew., Lupinus micranthus Guss.) and rough-seeded (Lupinus cosentinii Guss. and Lupinus pilosus Murr.) lupin species. Comparative cytogenetic mapping was done using FISH with oligonucleotide probes and previously published chromosome-specific bacterial artificial chromosome (BAC) clones. Oligonucleotide probes were designed to cover both arms of chromosome Lang06 of the L. angustifolius reference genome separately. The chromosome was chosen for the in-depth study due to observed structural variability among wild lupin species revealed by BAC-FISH and supplemented by in silico mapping of recently released lupin genome assemblies. The results highlighted changes in synteny within the Lang06 region between the lupin species, including putative translocations, inversions, and/or non-allelic homologous recombination, which would have accompanied the evolution and speciation.

Chromatographic Fingerprinting of the Old World Lupins Seed Alkaloids: A Supplemental Tool in Species Discrimination

The total contents and qualitative compositions of alkaloids in seeds of 10 Old World lupin species (73 accessions) were surveyed using gas chromatography. The obtained results, combined with those for three lupin crops, Lupinus angustifolius, Lupinus albus, and Lupinus luteus, provide the most complete and up-to-date overview of alkaloid profiles of 13 lupin species originating from the Mediterranean Basin. The qualitative alkaloid compositions served as useful supplementary tools of species discrimination. On the basis of the most abundant major alkaloids, lupanine, lupinine, and multiflorine, the Old World lupin species were divided into four groups. Those containing lupanine (L. angustifolius, L. albus, and Lupinus mariae-josephi), containing lupinine (Lupinus luteus, Lupinus hispanicus, and Lupinus × hispanicoluteus), containing lupinine and multiflorine (Lupinus atlanticus, Lupinus palaestinus, Lupinus anatolicus, Lupinus digitatus, Lupinus pilosus, and Lupinus cosentinii), and containing multiflorine (Lupinus micranthus). Within a given group, certain species can be, in most cases, further distinguished by the presence of other major alkaloids. The discrimination of species based on the total alkaloid content was found to be less reliable because of the significant intra-species variations, as well as the influences of environmental factors on the seed alkaloid content.

Different effects of soil drought on soluble carbohydrates of developing Lupinus pilosus and Lupinus luteus embryos

The aim of this study was to compare the accumulation of soluble carbohydrates in embryos of two lupin species: cultivated <em>Lupinus luteus</em> (cv. Juno) and wild <em>L. pilosus</em>, developing on plants grown under normal soil humidity and soil drought. All analysed seeds accumulated soluble carbohydrates, including: monosaccharides, sucrose, cyclitols, galactosyl cyclitols and raffinose family oligosaccharides. Soil drought caused a nearly two-fold increase of soluble carbohydrate contents in both species. <em>L. pilosus</em> embryos however, responded to water deficiency by increasing the accumulation of cyclitols and galactosyl cyclitols, whereas <em>L. luteus</em> embryos enhanced accumulation of cyclitols and raffinose family oligosaccharides.

Composition of seed soluble carbohydrates and ultrastructural diversity of testa in lupins from the mediterranean region

This article present a comparison of soluble sugar levels in seeds of <em>Lupinus atlanticus</em>, <em>Lupinus cosentinii</em>, <em>Lupinus palaestinus</em> and <em>Lupinus pilosus</em>, <em>Lupinus hispanicus</em> subsp. <em>hispanicus</em> and <em>Lupinus luteus</em> of Juno variety. Considering that sugars are accumulated in embryos, only the embryonic tissues were used for biochemical analyses. Additionally, the share of testa and embryo in seed tissues was evaluated. The seed-coat thickness was measured using scanning electron microscopy. The seed coat had the largest share in seeds of <em>Lupinus pilosus</em> and <em>Lupinus palaestinus</em>, and the least share in seeds of <em>Lupinus hispanicus</em> subsp. <em>hispanicus</em> and <em>Lupinus luteus</em> of Juno variety. In the seed of <em>Lupinus pilosus</em> the thickness of the seed coat was 1100 µm, while in <em>Lupinus luteus</em> it was 300 µm. The analysed <em>Lupinus</em> seeds accumulated from 73 mg/g d.m. (dry matter of seed embryo) to 155 mg of soluble sugars/g d.m. The highest quantity of oligosaccharides of the raffinose series was found in seeds of <em>Lupinus luteus</em>, while the lowest amount in seed of <em>Lupinus palaestinus</em>. Galactosyl cyclitols appeared in largest amount in seeds of <em>Lupinus palaestinus</em> and <em>Lupinus pilosus</em>, appropriately 41.93 and 33.75 mg/g dm. The lowest amount of galactosyl cyclitols appeared in <em>Lupinus atlanticus</em>, <em>Lupinus cosentinii</em> and <em>Lupinus hispanicus</em>.

Phosphorus deficiency enhances plasma membrane H+-ATPase activity and citrate exudation in greater purple lupin (Lupinus pilosus)

The response of greater purple lupin (Lupinus pilosus L.) to a combination of phosphorus (P) deficiency and aluminium (Al) toxicity is unknown, and the mechanisms involved in the exudation of organic anions from greater purple lupin have not been reported. Therefore, plants grown with (+P) or without (–P) 250 µm P were exposed to 0 or 50 µm AlCl3 and the amount of organic anions exuded and the activities of plasma membrane H+-ATPase (E.C 3.6.3.6) and H+-pumps were investigated. Twenty days of P deficiency resulted in significantly reduced shoot growth and increased proteoid root formation. Exposure to 50 µm AlCl3 did not induce citrate exudation but did induce some malate exudation in –P plants. In contrast, P deficiency did induce exudation of citrate. Enhanced citrate exudation was attributed to the large increase in the activity of plasma membrane H+-ATPase and associated H+ transport. This was shown by the inhibitory effect of vanadate on plasma membrane H+-ATPase activity in vitro and on citrate exudation in vivo. However, vanadate did not suppress the exudation of malate. During 9 h of Al exposure, exudation of citrate showed a continuing increase for both –P and +P plants, while malate exudation increased only during the first 3 h, after which it rapidly declined. The total amount of organic anion exudation was significantly higher for –P plants. In the presence of 50 µm anion channel blockers [anthracene-9-carboxylic acid (A-9-C), niflumic acid (NIF) and phenylglyoxal (PG)], the exudation of citrate and malate was reduced by 25–40%. It was concluded that P deficiency induces citrate exudation by enhancing the activity of plasma membrane H+-ATPase and H+ export. In L. pilosus, exudation of organic anions occurs primarily in response to P deficiency but not Al toxicity. This contrasts with previous results obtained in Brassica napus L.