Physiological response of four wolfberry (Lycium Linn.) species under drought stress

We studied gas-exchange, chlorophyll pigments, lipid peroxidation, antioxidant enzymes, and biomass partitioning responses in seedlings of four wolfberry species （Lycium chinense Mill. var. potaninii （Pojark.） A. M. Lu, Lycium chinense Mill., Lycium barbarum L., and Lycium yunnanense Kuang ＆ A. M. Lu） under four water supply regimes. In all four species, drought affected seedlings in terms of chlorophyll content, net photosynthesis rate （Pn）＇ transpiration rate （E）, and lipid peroxidation. Drought also increased some antioxidant enzyme activities, such as peroxidase （POD）, catalase （CAT）, superoxide dismutase （SOD）, and ascorbate peroxidase （APX）. Significant changes in dry biomass partitioning also occurred in response to water stress. In particular, dry biomass of leaves and fruits decreased significantly. L. chinense Mill. and L. barbarum L. possessed greater drought tolerance and exhibited superior antioxidant processing ability and other related physiological traits compared to the other two species. L. chinense Mill. was the most tolerant to all levels of drought. In contrast,L, yunnanense Kuang ＆ A. M. Lu was more affected by water supply and had the lowest resistance to drought stress. These findings would provide some important information regarding genetic resources for future forest tree improvement in relation to drought tolerance.

Constructing the wolfberry(Lycium spp.) genetic linkage map using AFLP and SSR markers

Genetic linkage maps are important for quantitative trait locus(QTL) and marker-assisted selection breeding. The wolfberry(Lycium spp.) is an important food and traditional medicine in China. However, few construction genetic linkage maps have been reported because of the lack of genomic and genetic resources. In this study, a population of 89 F1 seedings was derived from a cross between two heterozygous parents, L. chinense var. potaninii ‘BF-01’(female)and L. barbarum var. auranticarpum ‘NH-01’(male), in order to construct a genetic linkage map using simple sequence repeat(SSR) and amplified fragment length polymorphism(AFLP) markers based on the double pseudo-test cross mapping strategy. The resulting genetic map consisted of 165 markers(74 AFLPs and 91 SSRs) distributed across 12 linkage groups and spanned a total length of 557.6 cM with an average distance of 3.38 cM between adjacent markers.The 12 linkage groups contained 3 to 21 markers and ranged in length from 8.6 to 58.3 cM. Twenty-nine segregated markers distributed in the map were mainly located on LG4 and LG9 linkage groups at P<0.05. This is the first linkage map of Lycium species using SSR and AFLP markers, which can serve as basis for improving genes and selective breeding of the genome assembly.

2-O-β-D-Glucopyranosyl-L-ascorbic acid,an ascorbic acid derivative isolated from the fruits of Lycium barbarum L.,ameliorates high fructose-induced neuroinflammation in mice:involvement of gut microbiota and leaky gut

Western diet(rich in highly refined sugar and fat)can induce a range of metabolic dysfunctions in animals and humans,including neuroinflammation and cognitive function decline.Neuroinflammation and cognitive impairment,two critical pathological characteristics of Alzheimer’s disease,have been closely associated with microbial alteration via the gut-brain axis.Thus,the present study aimed to investigate the influence of 2-O-β-D-glucopyranosyl-L-ascorbic acid(AA-2βG)isolated from the fruits of Lycium barbarum on preventing the high-fructose diet(HFrD)induced neuroinflammation in mice.It was found that AA-2βG prevented HFr D-induced cognitive deficits.AA-2βG also predominantly enhanced the gut barrier integrity,decreased lipopolysaccharide entry into the circulation,which subsequently countered the activation of glial cells and neuroinflammatory response.These beneficial effects were transmissible by horizontal fecal microbiome transplantation,transferring from AA-2βG fed mice to HFr D fed mice.Additionally,AA-2βG exerted neuroprotective effects involving the enrichment of Lactobacillus and Akkermansia,potentially beneficial intestinal bacteria.The present study provided the evidence that AA-2βG could improve indices of cognition and neuroinflammmation via modulating gut dybiosis and preventing leaky gut.As a potential functional food ingredient,AA-2βG may be applied to attenuate neuroinflammation associated with Western-style diets.

Impact of Different Rates of Nitrogen Supplementation on Soil PhysicochemicalProperties and Microbial Diversity in Goji Berry

Goji berry(Lycium barbarum L.)is substantially dependent on nitrogen fertilizer application,which can signifi-cantly enhance fruit yield and Goji berry industrial development in Ningxia,China.This study aimed to analyze the functions of differential nitrogen application rates including low(N1),medium(N2),and high(N3)levels in soil microbial community structure(bacterial and fungal)at 2 diverse soil depths(0-20,20-40 cm)through high-throughput sequencing technology by targeting 16S RNA gene and ITS1&ITS2 regions.All the observed physicochemical parameters exhibited significant improvement(p<0.05)with increased levels of nitrogen and the highest values for most parameters were observed at N2.However,pH decreased(p<0.05)gradually.The alpha and beta diversity analyses for bacterial and fungal communities’metagenome displayed more similarities than differences among all groups.The top bacterial and fungal phyla and genera suggested no obvious(p>0.05)differences among three group treatments(N1,N2,and N3).Furthermore,the functional enrichment analysis demonstrated significant(p<0.05)enrichment of quorum sensing,cysteine and methionine metabolism,and transcriptional machinery for bacterial communities,while various saprotrophic functional roles for fungal communities.Conclusively,moderately reducing the use of N-supplemented fertilizers is conducive to increasing soil nitrogen utilization rate,which can contribute to sustainable agriculture practices through improved soil quality,and microbial community structure and functions.

Cytological Observation of Pollen Abortion of Lycium barbarum Haploids from Anther Culture

To reveal the sterility characteristics of Lycium barbarum haploids, cytological observations were made on the anthers of Ningqi No.1 and its haploids obtained from anther culture. The results showed that there were no significant differences in anther development between Ningqi No.1 and its haploids at the stage of pollen mother cell, and tetrads were formed successfully after the meiosis stage. The tetrads of Ningqi No.1 could release microspores. At the same time, the tapetal cells can provide nutrition for the development of the microspores, which eventually developed into mature pollen grains. Although the haploids could also release microspores at the tetrad stage, the tapetal cells degraded in advance, which made the released microspores unable to develop into mature pollen grains, resulting in pollen abortion of haploids.

ERF5.1 modulates carotenoid accumulation by interacting with CCD4.1 in Lycium

Carotenoids are important natural pigments and have medical and health functions for humans.Carotenoid cleavage dioxygenase 4(CCD4)and ethylene responsive factor(ERF)participate in carotenoid metabolism,but their roles in Lycium have not been discovered.Here,we annotated LbCCDs from the Lycium reference genome and found that LbCCD4.1 expression was significantly correlated with the carotenoid metabolites during Lycium five fruit developmental stages.Over-expression of LbCCD4.1 in NQ’s leaves resulted in a series of significantly lower contents of carotenoid metabolites,includingβ-carotene andβ-cryptoxanthin.Moreover,LbERF5.1,a transcription factor belonging to the ERF family that was located in the nucleus,was isolated.Significant reductions in the carotenoids,especially lutein,violaxanthin and their derivatives,were observed in over-expressing ERF5.1 transgenic NQ’s leaves.Over-expression or virus-induced gene silencing of LbERF5.1 in NQ’s leaves induced a consistent up-or down-expression,respectively,of LbCCD4.1.Furthermore,yeast one-hybrid and dual-luciferase reporter assays showed that ERF5.1 interacted with the promoter of CCD4.1 to increase its expression,and LbERF5.1 could bind to any one of the three predicted binding sites in the promoter of LbCCD4.1.A transcriptome analysis of LbERF5.1 and LbCCD4.1 over-expressed lines showed similar global transcript expression,and geranylgeranyl diphosphate synthase,phytoene synthase,lycopeneδ-cyclase cytochrome,cytochrome P450-type monooxygenase 97A,cytochrome P450-type monooxygenase 97C,and zeaxanthin epoxidase in the carotenoid biosynthesis pathway were differentially expressed.In summary,we uncovered a novel molecular mechanism of carotenoid accumulation that involved an interaction between ERF5.1 and CCD4.1,which may be used to enhance carotenoid in Lycium.

Genetic Variation in Salt Stress Response and Germplasm Resource Evaluation among <i>Lycium</i>Accessions

Genetic variation between naturally occurring ecotypes can be helpful to elucidate the mechanism controlling salt stress response in different environments. The salt stress response of 20 natural accessions or cultivars of Lycium was characterized at a physiological level, following exposed to 300 mM NaCl for 15 days. It is shown that salt stress increased Na+, betaine and malondialdehyde (MDA) content, as well as the relative permeability of plasma membranes, but decreased K+, chlorophyll and glutathione (GSH) content, as well as K+/Na+ ratio compared with their respective control value in most of the varieties, though the increasing or decreasing extent has a clear genetic diversity. The physiological response was utilized to evaluate the salt-tolerant capacity of these varieties by principal component analysis and clustering analysis, and in which total chlorophyll, K+/Na+ ratio and partially GSH have the maximum weight relatively. These varieties could be categorized into four sub-groups, means greatly resistance (Heiguo, Ninqi No. 2 and Beifang), moderately resistant, sensitive, and mostly sensitive (Ninqi No. 7) to salt stress. Our results provide a theoretical basis and practical guidance for the improvement of saline-alkali land and rational utilization of Lycium germplasm resources in the future.

Research and application of Lycii Fructus in medicinal field

Lycii Fructus（Lycium barbarum, Gouqizi in Chinese name） is one of the most popular Chinese material medica and a common ingredient in tonic food. This fruit has been paid rapidly growing attention for its nutrient value and noticeable pharmacological properties. The present paper focuses on the legal resource of Gouqizi and reviews the main research in medicinal field including botanical identification,ethnopharmacological functions, phytochemistry, pharmacological effects, clinic usages, and safety issues.In addition, some issues needed address will be also discussed. We strongly believe that further investigation will deepen our knowledge of Gouqizi and promote the industrial development in the world.