Two novel species isolated from wheat rhizospheres in Serbia: Pseudomonas serbica sp. nov. and Pseudomonas serboccidentalis sp. nov.

Pseudomonas strains IT-194P, IT-215P, IT-P366^T and IT-P374^T were isolated from the rhizospheres of wheat grown in soils sampled from different fields (some of them known to be disease-suppressive) located near Mionica, Serbia. Phylogenetic analysis of the 16S rRNA genes and of whole genome sequences showed that these strains belong to two potentially new species, one containing strains IT-P366^T and IT-194P and clustering (whole genome analysis) next to P. umsongensis DSM16611^T, and another species containing strains IT-P374^T and IT-215P and clustering next to P. koreensis LMG21318^T. Genome analysis confirmed the proposition of novel species, as ANI was below the threshold of 95% and dDDH below 70% for strains IT-P366^T (compared with P. umsongensis DSM16611^T) and IT-P374^T (compared with P. koreensis LMG21318^T). Unlike P. umsongensis DSM16611^T, strains of P. serbica can grow on D-mannitol, but not on pectin, D-galacturonic acid, L-galactonic acid lactone and α-hydroxybutyric acid. In contrary to P. koreensis LMG21318^T, strains of P. serboccidentalis can use sucrose, inosine and α-ketoglutaric acid (but not L-histidine) as carbon sources. Altogether, these results indicate the existence of two novel species for which we propose the names Pseudomonas serbica sp. nov., with the type strain IT-P366^T (=CFBP 9060 ^T = LMG 32732 ^T = EML 1791 ^T) and Pseudomonas serboccidentalis sp. nov., with the type strain IT-P374^T (=CFBP 9061 ^T = LMG 32734 ^T = EML 1792 ^T). Strains from this study presented a set of phytobeneficial functions modulating plant hormonal balance, plant nutrition and plant protection, suggesting a potential as Plant Growth-Promoting Rhizobacteria (PGPR).     

Intestinal morphology in oily bitterlings (Cyprinidae: Acheilognathinae)

We evaluated inter- and intraspecific variations of the intestinal coiling patterns and intestinal length of the oily bitterlings, Tanakia limbata, Tanakia koreensis, Tanakia somjinensis, and Tanakia signifer. All the oily bitterling species shared a unique intestinal coiling pattern, expressed as an oval shaped loop. The ratio of the intestinal length to standard length varied among species, viz., both T. koreensis and T. signifer have significantly longer intestines than T. limbata and T. somjinensis. The intestinal length may be a useful diagnostic character between two sibling species, T. koreensis and T. somjinensis, although we observed intraspecific variation in the intestinal length of T. limbata and T. koreensis among collection sites.     

Virgibacillus albus sp. nov., a novel moderately halophilic bacterium isolated from Lop Nur salt lake in Xinjiang province, China

A Gram-positive, moderately halophilic, strictly aerobic bacterium, designated YIM 93624^T, was isolated from a salt lake in Xinjiang province of China and subjected to a polyphasic taxonomic study. Strain YIM 93624^T grew at 15–45 °C (optimum 25–30 °C), 1–17% (w/v) NaCl (optimum 5–10 %, w/v) and pH 4.0–9.0 (optimum pH 7.0). The predominant menaquinone was found to be MK-7. The major fatty acids were anteiso-C_15:0 and C_16:0. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, a glycolipid and two unidentified phospholipids. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The G+C content of the genomic DNA was 37.9 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM 93624^T was a member of the genus Virgibacillus and exhibited the highest similarity of 97.0 % to Virgibacillus koreensis KCTC 3823^T. However, the level of DNA–DNA relatedness between strain YIM 93624^T and V. koreensis KCTC 3823^T was 32.5 %. On the basis of phylogenetic, physiological and chemotaxonomic analysis data, the isolate is concluded to represent a novel species of the genus Virgibacillus, for which the name Virgibacillus albus sp. nov., is proposed, with type strain of YIM 93624^T (=DSM 23711^T = JCM 17364^T).     

Kocuria uropygioeca sp. nov. and Kocuria uropygialis sp. nov., isolated from the preen glands of Great Spotted Woodpeckers (Dendrocopos major)

Two new species of Gram-positive cocci were isolated from the uropygial glands of wild woodpeckers (Dendrocopos major) originating from different locations in Germany. A polyphasic approach confirmed the affiliation of the isolates to the genus Kocuria. Phylogenetic analysis based on the 16S rRNA gene showed high degree of similarity to Kocuria koreensis DSM 23367^T (99.0% for both isolates). However, low ANIb values of <80% unequivocally separated the new species from K. koreensis. This finding was further corroborated by DNA fingerprinting and analysis of polar lipid profiles. Furthermore, growth characteristics, biochemical tests, MALDI-TOF MS analysis, and G + C contents clearly differentiated the isolates from their known relatives. Besides, the woodpecker isolates significantly differed from each other in their whole-cell protein profiles, DNA fingerprints, and ANIb values. In conclusion, the isolated microorganisms constitute members of two new species, for which the names Kocuria uropygioeca sp. nov. and Kocuria uropygialis sp. nov. are proposed. The type strains are 36^T (DSM 101740^T = LMG 29265^T) and 257^T (=DSM 101741^T = LMG 29266^T) for K. uropygialis sp. nov. and K. uropygioeca sp. nov., respectively.     

Characterization of 11 novel polymorphic microsatellite loci in the threatened Korean loach,Iksookimia koreensis,isolated using a next-generation sequencing method

To investigate the genetic diversity and population structure of Iksookimia koreensis, we characterized 11 novel polymorphic microsatellite markers developed using next-generation sequencing. The number of alleles per locus ranged from 4 to 10 (average = 6.26). Observed and expected heterozygosities ranged from 0.333 to 0.866 and from 0.375 to 0.866, respectively. No loci showed significant deviation from Hardy–Weinberg equilibrium (HWE). These loci were also used successfully to study the genetic diversity of a closely related species, Iksookimia longicorpa. Four of the 11 loci amplified in the two species showed different allele frequency and distribution, indicating deep genetic divergence between I. koreensis and I. longicorpa. The newly developed microsatellite markers reported here will provide a useful tool for examining gene flow, population genetic structure, and genetic diversity of these species.     

Stenotrophomonas chelatiphaga sp. nov., a new aerobic EDTA-degrading bacterium

A new ethylenediaminetetraacetic acid (EDTA)-utilizing gammaproteobacterial strain LPM-5^T was isolated from municipal sewage sludge. Aerobic, gram-negative, motile rods multiply by binary fission. Neutrophilic and mesophilic, these are unable to grow in the presence of 3% NaCl (w/v), and unable to reduce nitrate to nitrite, and are oxidase and catalase positive, but lipase negative. The major cellular fatty acids are C_i15:0, C_a15:0 and C_16:1w7c. The dominant phospholipids are phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol (cardiolipin). The DNA G+C content is 68.3 mol% (T_m). The 16S rRNA gene sequence analysis showed a high similarity of strain LPM-5^T to the species members of genus Stenotrophomonas: S. maltophilia LMG 958^T (98.6%), S. rhizophila CCUG 47042^T (98.3%), S. koreensis TR6-01^T (97.6%) and S. acidaminiphila CIP 106456^T (97.0%). Based on these results and modest DNA–DNA hybridization levels with S. maltophilia VKM B-591^T (=LMG 958^T) (51%) and S. rhizophila CCUG 47042^T (52%), the isolate was classified as a novel species, Stenotrophomonas chelatiphaga sp. nov. (type strain LPM-5^T=VKM B-2486=DSM-21508=CCUG 57178).     

Molecular evidence for the inclusion of the Korean endemic genus “<Emphasis Type="Italic">Echinosophora</Emphasis>” in<Emphasis Type="Italic"> Sophora</Emphasis> (Fabaceae), and embryological features of the genus

Although Echinosophora Nakai has been known as a monotypic and endemic genus of Papillionoideae of Fabaceae in Korea, it has been controversial whether it is distinct from or merged with Sophora. To resolve this matter, we conducted molecular phylogenetic analyses using nucleotide sequence data from the plastid rbcL gene and trnL (UAA) intron. Parsimony analysis, using a total of 53 taxa of the Papillionoideae (including E. koreensis [Nakai] Nakai and several species of Sophora and related genera) and using 20 taxa of Caesalpinioideae and Mimosoideae as outgroups, showed that, although the examined species of Sophora are split into two clades, E. koreensis formed a common clade with S. tomentosa (the type species of the genus) and S. flavescens. E. koreensis therefore should be treated as S. koreensis Nakai, and the generic name Echinosophora be eliminated. We also investigated the embryology of S. koreensis (=E. koreensis) and S. flavescens and found that no differences existed between them. Our molecular study, like other studies, strongly suggested that Sophora is polyphyletic. In this study we presented a summary of embryological features of the core Sophora for future critical comparison with related and unrelated taxa.     

Sequence specific integration by the family 1 casposase from Candidatus Nitrosopumilus koreensis AR1

Casposase, a homolog of Cas1 integrase, is encoded by a superfamily of mobile genetic elements known as casposons. While family 2 casposase has been well documented in both function and structure, little is known about the other three casposase families. Here, we studied the family 1 casposase lacking the helix-turn-helix (HTH) domain from Candidatus Nitrosopumilus koreensis AR1 (Ca. N. koreensis). The determinants for integration by Ca. N. koreensis casposase were extensively investigated, and it was found that a 13-bp target site duplication (TSD) sequence, a minimal 3-bp leader and three different nucleotides of the TSD sequences are indispensable for target specific integration. Significantly, the casposase can site-specifically integrate a broad range of terminal inverted repeat (TIR)-derived oligonucleotides ranging from 7-nt to ∼4000-bp, and various oligonucleotides lacking the 5′-TTCTA-3′ motif at the 3′ end of TIR sequence can be integrated efficiently. Furthermore, similar to some Cas1 homologs, the casposase utilizes a 5′-ATAA-3′ motif in the TSD as a molecular ruler to dictate nucleophilic attack at 9-bp downstream of the end of the ruler during the spacer-side integration. By characterizing the family 1 Ca. N. koreensis casposase, we have extended our understanding on mechanistic similarities and evolutionary connections between casposons and the adaptation elements of CRISPR-Cas immunity.     

Rhodococcus kronopolitis sp. nov., a novel actinobacterium isolated from a millipede (Kronopolites svenhedind Verhoeff)

A novel actinobacterium, designated strain NEAU-ML12^T, was isolated from a millipede (Kronopolites svenhedind Verhoeff), which was collected from Fenghuang Mountain in Wuchang, Heilongjiang Province, north China. The strain was characterized using a polyphasic approach. Strain NEAU-ML12^T was found to have morphological and chemotaxonomic characteristics typical of the members of the genus Rhodococcus. 16S rRNA gene sequence similarity analysis showed that the strain NEAU-ML12^T belongs to the genus Rhodococcus, and was most closely related to Rhodococcus tukisamuensis Mb8^T (98.9 %) and Rhodococcus koreensis DNP505^T (97.7 %). Phylogenetic analysis based on 16S rRNA gene sequences also demonstrated that strain NEAU-ML12^T should be classified in the genus Rhodococcus, forming a distinct clade with R. tukisamuensis Mb8^T supported by a 99 % bootstrap value. However, the DNA–DNA relatedness between strain NEAU-ML12^T and R. tukisamuensis Mb8^T was found to be 41.9 ± 0.7 %. Furthermore, strain NEAU-ML12^T could also be differentiated from R. tukisamuensis Mb8^T and other closely related strains (R. koreensis DNP505^T and Rhodococcus maanshanensis M712^T) by morphological and physiological characteristics. Therefore, it is proposed that strain NEAU-ML12^T represents a novel species of the genus Rhodococcus, for which the name Rhodococcus kronopolitis sp. nov. is proposed. The type strain is NEAU-ML12^T (=CGMCC 4.7145^T = DSM 46702^T).     

Dyella jejuensis sp. nov., isolated from soil of Hallasan Mountain in Jeju Island

A novel bacterium, designated JP1^T, was isolated from soil of Hallasan Mountain in Jeju Island. The isolate was a Gramnegative, aerobic, motile and rod-shaped (0.2–0.4 × 1.2–2.0 μm) bacterium. Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain JP1^T was closely related to Dyella koreensis with 97.6% similarity. Growth of strain JP1^T occurred at 10–37°C, pH 5–7 and 0–1% (w/v) NaCl. The genomic DNA G+C content of strain JP1^T was 62.1 mol%. The major fatty acids were iso-C_16:0, iso-C_17:1 ω9c, and iso-C_15:0. The predominant quinone was ubiquinone-8. The major polar lipids of strain JP1^T were phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, unidentified aminolipids and unidentified aminophospholipids. The DNA-DNA relatedness values between strain JP1^T and previously reported Dyella species were <10%. Based on phenotypic, genotypic, and phylogenetic distinctness, strain JP1^T represents a novel species in the genus Dyella, for which the name Dyella jejuensis sp. nov. is proposed. The type strain is JP1^T (=KACC 17701^T =JCM 19615^T).     

A new bacterial strain, <Emphasis Type="Italic">Pseudomonas koreensis</Emphasis> IB-4, as a promising agent for plant pathogen biological control

A bacterial strain IB-4, antagonistic to plant pathogenic fungi of the genera Fusarium, Bipolaris, and Alternaria, was isolated from arable soils of the Mechetlinskii district, Bashkortostan. Physiological, biochemical, and culture morphological properties of strain IB-4 supported its classification within the genus Pseudomonas. In spite of some discrepancies in the results of phenotypic and chemotaxonomic research, analysis of the 16S rRNA gene sequence, DNA–DNA hybridization, GC-content, and MALDI mass spectral data provide considerable evidence supporting its identification as a Pseudomonas koreensis strain. P. koreensis strain IB-4 was shown to possess the valuable features characteristic of PGPR microorganisms: antifungal and nitrogenase activities and ability to synthesize indole-3-acetic acid (IAA) and cytokinin-like compounds. Field test, in which potato plants were treated with the culture liquid of P. koreensis strain IB-4 revealed a positive effect on potato yield and resistance to plant pathogens.     

Tahibacter aquaticus gen. nov., sp. nov., a new gammaproteobacterium isolated from the drinking water supply system of Budapest (Hungary)

Three Gram-stain negative, aerobic, non-motile, non-spore-forming, rod-shaped bacterial strains, PYM5-11^T, RaM5-2 and PYM5-8, were isolated from the drinking water supply system of Budapest (Hungary) and their taxonomic positions were investigated by a polyphasic approach. All three strains grew optimally at 20-28 °C and pH 5-7 without NaCl. The G+C content of the DNA of the type strain was 65.4 mol%. On the basis of 16S rRNA gene sequence analysis, the isolates showed 94.5-94.9% sequence similarity to the type strain of Dokdonella koreensis and a similarity of 93.0-94.1% to the species of the genera Aquimonas and Arenimonas. The major isoprenoid quinone of the strains was ubiquinone Q-8. The predominant fatty acids were iso-C_15:0, iso-C_17:1ω9c, C_16:1ω7c, and C_16:0. Diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phosphatidylmonomethylethanolamine, as well as several unidentified aminolipids and phospholipids were present. The 16S rRNA gene sequence analysis, the predominant fatty acids, the polar lipid composition, RiboPrint patterns, physiological and biochemical characteristics showed that the three strains were related but distinct from the type strains of the four recognized species of the genus Dokdonella, and indicated that the strains represented a new genus within the Gammaproteobacteria. The strain PYM5-11 (=DSM 21667^T=NCAIM B 02337^T) is proposed as the type strain of a new genus and species, designated as Tahibacter aquaticus gen. nov., sp. nov.     

Caenimonas terrae sp. nov., isolated from a soil sample in Korea, and emended description of the genus Caenimonas Ryu et al. 2008

A white-coloured bacterium, SGM1-15^T, was isolated from a paddy soil sample from Suwon, Republic of Korea. The cells were strictly aerobic, Gram-negative and curved rod-shaped. A phylogenetic analysis based on 16S rRNA gene sequences revealed that strain SGM1-15^T was closely related to Curvibacter delicatus LMG 4328^T (97.6% similarity) and Caenimonas koreensis EMB320^T (97.5% similarity). The major respiratory quinone system was Q-8 and the predominant cellular fatty acids were C_16:0 (39.9%), summed feature 3 (C_16:1 ω7c and/or iso-C_15:0 2-OH; 24.3%) and C_17:0 cyclo (22.7%). The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The major polyamines were 2-hydroxypurescine, purescine and spermidine. The DNA G+C content was 68.7 mol%. On the basis of the phylogenetic, physiologicl and chemotaxonomic data, stain SGM1-15^T represents a novel species of the genus Caenimonas, for which the name Caenimonas terrae sp. nov. is proposed. The type strain of Caenimonas terrae is SGM1-15^T (=KACC 13365^T =NBRC 106341^T).     

Nocardioides panaciterrulae sp. nov., isolated from soil of a ginseng field, with ginsenoside converting activity

A Gram-positive, coccoid to rod-shaped, non-spore-forming bacterium, designated Gsoil 958^T, was isolated from soil of a ginseng field located in Pocheon province in South Korea. This bacterium was characterized in order to determine its taxonomic position by using a polyphasic approach. Strain Gsoil 958^T was observed to grow well at 25–30 °C and at pH 7.0 on R2A and nutrient agar without NaCl supplementation. Strain Gsoil 958^T was determined to have β-glucosidase activity and the ability to transform ginsenoside Rb₁ (one of the dominant active components of ginseng) to F₂ via gypenoside XVII and Rd. On the basis of 16S rRNA gene sequence similarity, strain Gsoil 958^T was shown to belong to the family Nocardioidaceae and related most closely to Nocardioides koreensis MSL-09^T (97.6 % 16S rRNA gene sequence similarity), Nocardioides aquiterrae GW-9^T (97.0 %), and Nocardioides sediminis MSL-01^T (97.0 %). The sequence similarities with other validly named species within the genus Nocardioides were less than 96.8 %. Strain Gsoil 958^T was characterized chemotaxonomically as having LL-2,6-diaminopimelic acid in the cell-wall peptidoglycan, MK-8(H₄) as the predominant menaquinone, and iso-C_16:0, iso-C_16:1 H, iso-C_14:0, iso-C_15:0 were identified as the major fatty acids. The G + C content of genomic DNA was determined to be 70.8 mol %. The chemotaxonomic properties and phenotypic characteristics supported the affiliation of strain Gsoil 958^T to the genus Nocardioides. The results of both physiological and biochemical tests allowed for differentiation of strain Gsoil 958^T from the recognized Nocardioides species. Therefore, strain Gsoil 958^T is considered to represent a novel species of the genus Nocardioides, for which the name Nocardioides panaciterrulae sp. nov. is proposed, with the type strain Gsoil 958^T (KACC 14271^T = KCTC 19471^T = DSM 21350^T).     

N-(3-oxobutyl)cytisine: A new lupin alkaloid from eChinosophora koreensis

A new lupin alkaloid, N-(3,-oxobutyl)cytisine, was isolated from the aerial parts of Echinosophora koreensis. Its structure was determined by s     

Pedobacter namyangjuensis sp. nov. isolated from soil and reclassification of Nubsella zeaxanthinifaciens Asker et al. 2008 as Pedobacter zeaxanthinifaciens comb. nov.

A Gram-stain-negative, non-motile, strictly aerobic, yellow-pigmented bacterium, designated strain 5G38^T, was isolated from a field cultivated with Chinese cabbage in Korea. The strain grew at 5–40°C and at pH 6.0–8.0. 16S rRNA gene sequence analysis revealed that strain 5G38^T represented a distinct lineage within the family Sphingobacteriaceae and showed the highest 16S rRNA gene sequence similarity of 95.2% with Pedobacter koreensis WPCB189^T, followed by Pedobacter agri PB92^T (94.6%), Pedobacter suwonensis 15–52^T (94.4%), Pedobacter rhizosphaerae 01–96^T (94.4%), Pedobacter sandarakinus DS-27^T (94.4%), and Nubsella zeaxanthinifaciens TDMA-5^T (94.3%). Strain 5G38^T formed monophyletic clade with Nubsella zeaxanthinifaciens in the cluster comprised of species of the genus Pedobacter. Chemotaxonomic characteristics of the novel strains, including DNA G+C content of genomic DNA (37.0 mol%), the predominant respiratory quinine (MK-7), and the major fatty acids which were iso-C_15:0, summed feature 3 (comprising C_16:1 ω7c and/or iso-C_15:0 2-OH) and iso-C_17:0 3-OH, are similar to those of the genus Pedobacter. However, the novel strains can be distinguished from the other species of Pedobacter by physiological properties. The name Pedobacter namyangjuensis sp. nov. is therefore proposed for strain 5G38^T (KACC 13938^T =NBRC 107692^T) as the type strain. Furthermore, the reclassification of Nubsella zeaxanthinifaciens as Pedobacter zeaxanthinifaciens comb. nov. is proposed.     

Isolation and characterization of lactic acid bacteria strains with ornithine producing capacity from natural sea salt

Two lactic acid bacteria (LAB) having ornithine-producing capacity were isolated from Korean natural sea salt. They were Gram-positive, short rod-type bacteria, and able to grow anaerobically with CO₂ production. The isolates grew well on MRS broth at 30–37°C and a pH of 6.5–8.0. The optimum temperature and pH for growth are 37°C and pH 7.0. The isolates fermented D-ribose, D-galactose, D-lactose, D-maltose, Dcellobiose, D-tagatose, D-trehalose, sucrose, D-melezitose, gentiobiose, D-glucose but not D-melibiose, inositol, and L-sorbose. The 16S rDNA sequences of the two isolates showed 99.5% and 99.6% homology with the Weissella koreensis S5623 16S rDNA (Access no. AY035891). They were accordingly identified and named as Weissella koreensis MS1-3 and Weissella koreensis MS1-14, and produced intracellular ornithine at levels of 72 mg/100 g cell F.W. and 105 mg/100 g cell F.W. and extracellular ornithine at levels of 4.5 mg/100 ml and 4.6 mg/100 ml medium, respectively, by culturing in MRS broth supplemented with 1% arginine. High cell growth was maintained in MRS broth with a NaCl concentration of 0–6%. These results show for the first time that Korean natural sea salts contain lactic acid bacteria Weissella koreensis strains having ornithine producing capacity.     

Lupin alkaloids from flowers of Echinosophora koreensis

(?)-Methyl 12-cytisineacetate (2) was isolated from methanol extracts of fresh flowers of Echinosophora koreensis together with seven known lupin alkaloids. Ethyl 12-cytisineacetate (3) was also isolated from ethanol extracts of the same flowers. Compounds 2 and 3 were artifacts and (?)-12-cytisineacetic acid (4) is assumed to be the principal source of 2 and 3. The variations in alkaloid content during growth of the flowers and the seedlings were also examined.     

A review of the genera Gnathochorisis F?rster and Symplecis F?rster of South Korea,with notes on Korean orthocentrines (Hymenoptera,Ichneumonidae, Orthocentrinae)

Two genera of Korean Orthocentrinae, Gnathochorisis and Symplecis, are reviewed, and keys to species of these genera are provided here. Two new species, Gnathochorisis fuscipes Humala & Lee, sp. n. and Gnathochorisis koreensis Humala & Lee, sp. n. are described from South Korea. The current state of the taxonomy of Eastern Palaearctic orthocentrines is briefly discussed.     

Low Temperature-Induced Decrease in trans-Delta-Hexadecenoic Acid Content Is Correlated with Freezing Tolerance in Cereals

The effect of growth at 5°C on the trans-Δ³-hexadecenoic acid content of phosphatidyl(d)glycerol was examined in a total of eight cultivars of rye (Secale cereale L.) and what (Triticum aestivum L.) of varying freezing tolerance. In these monocots, low temperature growth caused decreases in the trans-Δ³-hexadecenoic acid content of between 0 and 74% with concomitant increases in the palmitic acid content of phosphatidyl(d)glycerol. These trends were observed for whole leaf extracts as well as isolated thylakoids. The low growth temperature-induced decrease in the trans-Δ³-hexadecenoic acid content was shown to be a linear function (r² = 0.954) of freezing tolerance in these cultivars. Of the six cold tolerant dicotyledonous species examined, only Brassica and Arabidopsis thaliana L. cv Columbia exhibited a 42% and 65% decrease, respectively, in trans-Δ³-hexadecenoic acid content. Thus, the relationship between the change in trans-Δ³-hexadecenoic acid content of phosphatidyl(d)glycerol and freezing tolerance cannot be considered a general one for all cold tolerant plant species. However, species which exhibited a low growth temperature-induced decrease in trans-Δ³-hexadecenoic acid also exhibited a concomitant shift in the in vitro organization of the light harvesting complex II from a predominantly oligomeric form to the monomeric form. We conclude that the proposed role of phosphatidyl(d)glycerol in modulating the organization of light harvesting complex II as a function of growth temperature manifests itself to varying degrees in different plant species. A possible physiological role for this phenomenon with respect to low temperature acclimation and freezing tolerance in cereals is discussed.