Sea Buckthorn Subspecies Research Articles

Authentication of Hippophae rhamnoides ssp. sinensis and ssp. mongolica Based on Single Nucleotide Polymorphism at Ribosomal DNA and Their Vitamin Content Analysis.

Hippophae rhamnoides widely known as sea buckthorn berries (SB) are rich in vitamins and phytonutrients. The subspecies ssp. sinensis and ssp. mongolica are highly valued for their medicinal properties and vitamin contents, hence domesticated widely across Eurasia and Southeast Asia. Due to the frequent usage of these two subspecies, accurate identification is required to prevent economically motivated adulteration. In this study, we report the single nucleotide polymorphism (SNP) based molecular markers to easily distinguish these two subspecies at 45S nrDNA region. From the determined 45S rDNA region, we designed two primers (5′ sinensis and 5′ mongolica) and developed a multiplex PCR profile. The developed primers effectively distinguished the sea buckthorn subspecies in commercial products as well. Along with the development of subspecies specific primers, we have profiled vitamin contents from H. rhamnoides ssp. sinensis and ssp. mongolica and found ascorbic acid and riboflavin contents were high in both ssp. sinensis and spp. mongolica, yet the content of folic acid was high only in ssp. mongolica. Thus, we provide species specific primers and vitamin profile as an effective authentication of H. rhamnoides.

An ABA-flavonoid relationship contributes to the differences in drought resistance between different sea buckthorn subspecies.

Drought is the most severe abiotic stress and hinders the normal growth and development of plants. Sea buckthorn (Hippophae rhamnoides Linn.) is a typical drought-resistant tree species. In this study, the leaves of the H. rhamnoides ssp. sinensis ('FN') and H. rhamnoides ssp. mongolica ('XY') were selected during drought-recovery cycles for RNA sequencing, and physiological and biochemical analyses. The results revealed that drought stress significantly decreased leaf water potential, net photosynthetic rate and stomatal conductance in both sea buckthorn subspecies. Similarly, the contents of flavone, flavonol, isoflavone and flavanone significantly decreased under drought stress in 'XY'. Conversely, in 'FN', the flavone and abscisic acid (ABA) contents were significantly higher under drought stress and recovered after rehydration. Meanwhile, 4618 and 6100 differentially expressed genes (DEGs) were identified under drought stress in 'FN' and 'XY', respectively. In total, 5164 DEGs were observed in the comparison between 'FN' and 'XY' under drought stress. This was more than the 3821 and 3387 DEGs found when comparing the subspecies under control and rehydration conditions, respectively. These DEGs were mainly associated with carotenoid biosynthesis, flavonoid biosynthesis, photosynthesis and plant hormone signal transduction. Six hub DEGs (ABCG5, ABCG22, ABCG32, ABCG36, ABF2 and PYL4) were identified to respond to drought stress based on weighted gene co-expression network analysis and Basic Local Alignment Search Tool (BLAST) analysis using DroughtDB. These six DEGs were annotated to play roles in the ABA-dependent signaling pathway. Sixteen RNA sequencing results involving eight genes and similar expression patterns (12/16) were validated using quantitative real-time Polymerase Chain Reaction (PCR). The biochemical and molecular mechanisms underlying the regulation of drought responses by ABA and flavonoids in sea buckthorn were clarified. In this study, gene co-expression networks were constructed, and the results suggested that the mutual regulation of ABA and flavonoid signaling contributed to the difference in drought resistance between the different sea buckthorn subspecies.

TOCOPHEROLS OF FRUIT PULP OF FOUR SEABUCKTHORN (HIPPOPHAE RHAMNOIDES L.) SUBSPECIES IN FOREST-STEPPE CONDITIONS OF ALTAI TERRITORY

The aim of the study was to study tocopherols in the fruits of various sea buckthorn ecotypes ssp. mongolica in comparison with other subspecies. The composition of tocopherols in fruit pulp of four subspecies of sea buckthorn – H. rhamnoides ssp. mongolica, ssp. turkestanica, ssp. fluviatilis and ssp. carpatica, growing at Lisavenko Research Institute of Horticulture for Siberia in forest-steppe conditions of Altai territory has been studied. The research has been focused on the most promising subspecies from the point of view of industrial utilization – H. rhamnoides ssp. mongolica, in order to identify possible variation in accumulation of different tocopherols in fruit pulp depending on ecotype, period of collection of fruits as well as conditions of the year.
 It was established that the major tocopherol in the pulp of the fruit of sea buckthorn is α-tocopherol. β -, γ-and δ-tocopherols were characterized by low content. Within subspecies H. rhamnoides ssp. mongolica most fractions of tocopherols (except δ-tocopherol) have relatively high coefficient of variation, which exceeds of that for the whole group of evaluated varieties. That result does not allow us to use this criteria as a reliable background for preliminary systematic identification of evaluated varieties.

Comparative assessment of phytochemical profiles, antioxidant and antiproliferative activities of Sea buckthorn (Hippophaë rhamnoides L.) berries

Phytochemical profiles, antioxidant and antiproliferative activities of berry extracts were evaluated and compared in four subspecies of Sea buckthorn (Hippophaë rhamnoides L.). Among the subspecies, Hippophaë rhamnoides L. subsp. sinensis exhibited highest total phenolics content (38.7±1.3mgGA equiv./g DW) and corresponding total antioxidant activity. Whereas maximum cellular antioxidant and antiproliferative activities were determined in Hippophaë rhamnoides L. subsp. yunnanensis. Total antioxidant activity was significantly associated to total phenolics, isorhamnetin-3-rutinoside and isorhamnetin-3-glucoside. The cellular antioxidant activity and antiproliferative activity of phytochemicals were fairly correlated to phenolic acids and flavonoid aglycones. Lower median effective dose (EC50) of individual compounds against human liver cancer HepG2 cells proliferation studies confirmed the better correlation between antiproliferative activity of Sea buckthorn extracts and flavonoid aglycones, including isorhamnetin, quercetin and kaempferol.

Flavonol glycosides in berries of two major subspecies of sea buckthorn (Hippophaë rhamnoides L.) and influence of growth sites

Flavonol glycosides of wild sea buckthorn (Hippophaë rhamnoides ssp. sinensis) berries from China and cultivated berries (H. rhamnoides ssp. mongolica) from Finland and Canada were identified and quantified. Twenty-six flavonol glycosides were found with isorhamnetin and quercetin as the major aglycones. The contents of flavonol glycosides ranged 23–250mg/100g fresh berries and were significantly higher in the berries of ssp. sinensis than in those of ssp. mongolica. Among the cultivars of ssp. mongolica, the berries of ‘Oranzhevaya’ had the lowest (23mg/100g) content, and those of ‘Prevoshodnaya’ the highest content of flavonol glycosides (80mg/100g). Within the ssp. mongolica, the samples from Kittilä (Northern Finland) had higher levels of most flavonol glycosides than those from Turku (Southern Finland) and Québec. Among the ssp. sinensis berries of different growth sites, increasing trends were detected in the contents of most of the compounds as the altitude increased and as the latitude decreased. The wild berries (ssp. sinensis) from Sichuan had remarkably high contents and unique profiles of flavonol glycosides.

Fatty acids in berry lipids of six sea buckthorn (Hippophae rhamnoides L., subspecies carpatica) cultivars grown in Romania

BackgroundA systematic mapping of the phytochemical composition of different sea buckthorn (Hippophae rhamnoides L.) fruit subspecies is still lacking. No data relating to the fatty acid composition of main lipid fractions from the berries of ssp. carpatica (Romania) have been previously reported.ResultsThe fatty acid composition of the total lipids (oils) and the major lipid fractions (PL, polar lipids; FFA, free fatty acids; TAG, triacylglycerols and SE, sterol esters) of the oils extracted from different parts of six sea buckthorn berry subspecies (ssp. carpatica) cultivated in Romania were investigated using the gas chromatography-mass spectrometry (GC-MS). The dominating fatty acids in pulp/peel and whole berry oils were palmitic (23-40%), oleic (20-53%) and palmitoleic (11-27%). In contrast to the pulp oils, seed oils had higher amount of polyunsaturated fatty acids (PUFAs) (65-72%). The fatty acid compositions of TAGs were very close to the compositions of corresponding seed and pulp oils. The major fatty acids in PLs of berry pulp/peel oils were oleic (20-40%), palmitic (17-27%), palmitoleic (10-22%) and linoleic (10%-20%) acids, whereas in seeds PLs, PUFAs prevailed. Comparing with the other lipid fractions the SEs had the highest contents of saturated fatty acids (SFAs). The fatty acid profiles of the FFA fractions were relatively similar to those of TAGs.ConclusionsAll parts of the analyzed sea buckthorn berry cultivars (ssp. carpatica) exhibited higher oil content then the other European or Asiatic sea buckthorn subspecies. Moreover, the pulp/peel oils of ssp. carpatica were found to contain high levels of oleic acid and slightly lower amounts of linoleic and α-linolenic acids. The studied cultivars of sea buckthorn from Romania have proven to be potential sources of valuable oils.

Mechanisms Underlying Host Plant Selection by Holcocerus hippophaecolus Adults

We determined the mechanisms underlying host selection by adults of the seabuckthorn carpenterworm, Holcocerus hippophaecolus Hua, Chou, Fang et Chen. Four sea buckthorn (Hippophae rhamnoides L.) subspecies (varieties) with different degrees of resistance to H. hippophaecolus were chosen for artificial insect infection in cages. The results showed that olfactory and visual cues are very important for the selection of host plants by H. hippophaecolus, but that olfactory stimuli play a more vital role in this process. The relative abundance of branches and leaves had no effect on the likelihood that adults landed on plants from four subspecies (varieties), but did influence landing rates within the same subspecies (varieties). When considering only the most resistant sea buckthorn subspecies (varieties), the presence of luxuriant branches and leaves led to lower landing rates. These results provide a theoretical basis for the understanding of H. hippophaecolus damage to sea buckthorn and the means to implement effective measures of control.

Influence of origin, harvesting time and weather conditions on content of inositols and methylinositols in sea buckthorn ( Hippophaë rhamnoides) berries

Inositols and methylinositols play an important role in human physiology. Inositols and methylinositols in berries of three subspecies of sea buckthorn ( Hippophaë rhamnoides) were analysed using gas chromatography combined with a flame ionisation detector and mass spectrometry. The wild Chinese berries ( H. rhamnoides ssp. sinensis) contained higher levels of l-quebrachitol (1 l-2- O-methyl- chiro-inositol) and methyl- myo-inositol (average 615 and 58 mg/100 ml juice, respectively) than the Finnish ( H. rhamnoides ssp. rhamnoides, 276 and 11 mg/100 ml juice, respectively) and the Russian ( H. rhamnoides ssp. mongolica, 228 and 16 mg/100 ml juice, respectively) berries ( P < 0.001). The content of myo-inositol was higher in the Chinese and the Russian berries than in the Finnish berries (26 and 20 mg/100 ml juice vs. 8 mg/100 ml juice, P < 0.001). In the Chinese berries, the contents of methyl- myo-inositol and l-quebrachitol increased, whereas that of myo-inositol decreased from late September to late November. The content of the l-quebrachitol in the Chinese berries correlated negatively with the air temperature and the number of frost-free days, suggesting a possible role of the compound in the cold resistance of sea buckthorn.

NUTRITIONAL COMPONENTS AND NITROGEN FIXATION IN SEABUCKTHORN (HIPPOPHAE RHAMNOIDES L.)

Seabuckthorn (Hippophae rhamnoides L.) is an underutilized plant, except in China and some European countries where it is comparatively popular. Seabuckthorn is a small fruit tree in the family Elaeagnaceae that originated in Central Asia. This species offers many advantages in terms of nutrition, health and environmental sustainability due to its vitamin-rich fruit and its use of symbiotic nitrogen fixation. It also offers advantages in terms of food security and income generation because it is stress-tolerant and can be used in processed products. We compared the nutritional composition of the fruit produced by two subspecies of seabuckthorn, H. rhamnoides ssp. mongolica and ssp. rhamnoides. The mature fruit of both subspecies contained high levels of beta-carotene (provitamin A) and alpha-tocopherol (vitamin E); however, the amounts of beta-carotene and alpha-tocopherol were greater in the fruit of ssp. mongolica than in that of ssp. rhamnoides. Seabuckthorn fruit also contained high levels of L-ascorbic acid (vitamin C). The levels of sugars and acids known to be important in fruit flavor were also measured in both subspecies. We also analyzed symbiotic nitrogen fixation and stress tolerance in the plants, which may facilitate extensive sustainable cultivation. Seabuckthorn is useful for the greening of non-arable land and deserts. Seabuckthorn root nodules showed high levels of nitrogen-fixation activity, similar to that seen in Rhizobium-legume root nodules. Even under nitrogen-free conditions, seabuckthorn plants with root nodules grew normally. The morphology and 16S ribosomal DNA sequence of the root nodules indicated that the nodules were formed by Frankia, which belongs to the Elaeagnus group. Finally, seabuckthorn exhibited tolerance to drought and high temperature stress. Our results indicate that small actinorhizal fruit trees like seabuckthorn may be used to ensure food security and sustainable production. Thus, further characterization and the introduction of appropriate small actinorhizal fruit trees should be pursued.

Sugars, acids, ethyl β- d-glucopyranose and a methyl inositol in sea buckthorn ( Hippophaë rhamnoides) berries

Sea buckthorn berry is a rich source of nutrients and bioactive components beneficial for human health. Sugars and acids play an important role in determining the sensory properties of the berry. Sugars, acids, ethyl β- d-glucopyranose and a methyl inositol were analysed in berries of three subspecies ( Hippophaë rhamnoides ssp. sinensis, rhamnoides and mongolica) collected from China, Finland and Russia over four consecutive years. Fructose and glucose were the major sugars, and the dominating acids were malic and quinic acids. Origin and harvesting date have significant impacts on sugars, acids and sugar/acid ratio in the berry. During the harvesting period, the sugar content followed different changing patterns in berries of different subspecies. Ethyl glucose dominated in the sugar fraction of ssp. rhamnoides but existed only in trace amounts in the other two subspecies. In ssp. rhamnoides, the level of ethyl glucose increased during the harvesting period; the increase was accompanied by a decrease in glucose content, indicating the presence of a biochemical pathway converting glucose into its derivatives. A methyl inositol was identified for the first time in sea buckthorn with higher levels found in ssp. sinensis than in the other two subspecies. The levels of ethyl glucose and methyl inositol may be important sensory and nutritional quality factors of sea buckthorn berry. The data presented by this study provide important chemotaxonomic information characterising different subspecies of sea buckthorn and useful guidance for breeding, harvesting, and industrial utilisation of sea buckthorn.

Analysis of triacylglycerols of seeds and berries of sea buckthorn (Hippophaë rhamnoides) of different origins by mass spectrometry and tandem mass spectrometry

TAG of seeds, berries, and fruit pulp/peel of different subspecies of sea buckthorn (Hippophaë rhamnoides) were analyzed by MS and tandem mass spectrometry (MS/MS). The seeds contained mainly TAG with acyl carbon number (ACN) of 52 with 2-6 double bonds (DB) (20-30%), and TAG of ACN 54 with 3-9 DB (70-80%). In the pulp/peel fraction, the major TAG were species with ACN:DB of 48:1 to 48:3 (19-49%), 50:1 to 50:4 (31-41%), and 52:1 to 52:6 (9-19%). The molecular weight species of whole berries largely resembled those of fruit pulp/peel with additional species of ACN 54 from the seeds (5-24%). Subspecies (ssp.) sinensis differed from ssp. mongolica and rhamnoides by having a higher proportion of TAG of ACN 52 (27% vs. 21% and 22%, P< 0.05) and a lower proportion of ACN 54 (71% vs. 79% and 78%, P < 0.01) in seed TAG. Seed TAG of ssp. mongolica contained a higher proportion of more unsaturated species compared with those of the two other subspecies. Berry TAG of ssp. mongolica had the highest proportion of molecular species of ACN 48 due to the higher proportion of palmitic and palmitoleic acids and the lower seed content of the berries. Overall, palmitic acid favored the sn-1 and sn-3 positions. The order of preference of unsaturated FA for the sn-2 position depended at least partially on the FA combination of TAG. Seed TAG of ssp. mongolica contained a higher proportion of alpha-linolenic acid in the sn-2 position than those of ssp. sinensis. In berry TAG, ssp. mongolica had the highest proportions of palmitoleic and linoleic acids in the sn-2 position, and the lowest proportion of oleic/cis-vaccenic acid in the sn-2 position, among the three subspecies.

Fatty acid composition of lipids in sea buckthorn (Hippophaë rhamnoides L.) berries of different origins.

The oil content and fatty acid composition of berries from two subspecies of sea buckthorn (Hippophaë rhamnoides L.) were investigated. The berries of subsp. rhamnoides contained a higher proportion of oil in seeds (11.3% vs 7.3%, p < 0.01), berries (3.5% vs 2.1%, p < 0.001), and seedless parts (2.8% vs 1.7%, p < 0.01) than the berries of subsp. sinensis. Linoleic (18:2n-6) and alpha-linolenic acids (18:3n-3) comprised about 70% of seed oil fatty acids. Palmitoleic acid (16:1n-7), practically absent in the seed oil, comprised 12.1--39.0% of oil in pulp/peel and 8.9--31.0% of that in the whole berries. More linoleic acid (40.9% vs 39.1%) and less alpha-linolenic acid (26.6% vs 30.6%) was found in the seed oil of subsp. sinensis than in the seed oil of subsp. rhamnoides (p < 0.05). The proportion of palmitoleic acid was higher in the oil of berries of subsp. rhamnoides than the berries of subsp. sinensis (26.0% vs 21.5%, 0.05 < p < 0.1), but was vice versa with alpha-linolenic acid (8.8% vs 11.2%, 0.05 < p < 0.1). The proportions of alpha-linolenic acid correlated inversely with oleic and linoleic acids in the seed oil. In the oil of whole berries, the proportion of palmitoleic acid correlated negatively with the proportions of linoleic and alpha-linolenic acids.