Effects of saponin from the seed of Litchi chinensis Sonn on TGF-β1, FN and SOCS-1 in renal tubular epithelial cells under high glucose

Objective:To investigate the effect of saponin from the seed of Litchi chinensis Sonn(SLS)on the growth and apoptosis of human kidney epithelial cells(HKC)cultured in high glucose.Methods:HKC were cultured in DMEM/F12 medium supplemented with 30 mmol/L glucose and treated with or without SLS.In the normal group,isometric DMEM/F12 medium with 5.5mmol/L glucose was added.The secretion of TGF-β1 and fibronectin(FN)were detected by ELISA.Cell apoptosis was detected by the method of Annexin V-FITC/PI double staining.Western blot was used to detect the level of suppressor of cytokine signaling-1(SOCS-1).Results:The result of ELISA showed that the secretion of TGF-β1 and FN was decreased in SLS groups compared with those in 30 mmol/L glucose treated group(P<0.05).There were more cells apoptosis in 30 mmol/L glucose treated group than that in the normal group(P<0.01).Compared with the 30 mmol/L glucose treated group,the apoptosis of HKC were significantly decreased in SLS groups(P<0.01).Western blot showed that the level of SOCS-1 in high glucose+SLS group was decreased(P<0.01),compared with the high glucose group.Conclusion:SLS can reduce the secretion of TGF-β1 and FN in HKC by reducing the deposition of extracellular matrix.SLS also significantly reduced the apoptosis of HKC by inhibiting the level of SOCS-1.These results suggest the roles of SLS in preventing the progress of glomerular sclerosis.

Expression of SAMDC Gene for Enhancing the Shelf Life for Improvement of Fruit Quality Using Biotechnological Approaches into Litchi (Litchi chinensis Sonn.) Cultivars

Polyamines play an important role in plant response to abiotic stress. S-adenosyl-1-methionine decarboxylase (SAMDC) is one of the key regulatory enzymes in the biosynthesis of polyamines. In order to better understand the effect of regulation of polyamine biosynthesis on the shelf life improvement of litchi fruit, SAMDC cDNA isolated from Datura stramonium cloned in pBI121 was introduced into litchi genome by means of Agrobacterium tumefaciens through zygote disc transformation. Transgene and its expression are confirmed by Southern and Northern blot analyses, respectively. Transgenic plants expressing Datura SAMDC produced 1.7- to 2.4-fold higher levels of spermidine and spermine than wildtype plants under normal environmental condition, which indicated that the transgenic litchi presented an enhanced polyamines synthesis compared to wildtype plants. Our results demonstrated clearly that increasing polyamine biosynthesis in plants may be a means of creating improved fruit shelf life germplasm.

荔枝(Litchi chinensis Sonn.)叶片白化变异体遗传和转录组分析

为了解荔枝叶片白化变异体遗传特点,本研究以白化变异体比例较高的‘玉谭蜜荔’白化变异体苗与正常苗为试验材料,测定叶片叶绿素含量,并观测叶绿体结构差异,最后通过高通量测序技术对苗期叶片进行转录组测序分析。结果表明:‘玉谭蜜荔’种子实生苗中白化变异体的比例约为8.59%;白化苗叶片色素含量极低,仅为正常苗的0.519%;叶绿体的结构松散,基粒片层结构较少或缺失。对高通量测序数据进行组装和注释,共获得Unigene 42782条,平均长度987 bp,比对到Nr、KOG、KEGG、Swiss-prot四大数据库中,超过64%的Unigene序列获得注释,差异分析表明在细胞色素合成、光系统亚基合成蛋白、采光复合物a/b结合蛋白相关序列表达显著下调。本研究为该变异体的基因定位鉴定提供了一定的遗传基因注释信息。

Flavonoids from Litchi(Litchi chinensis Sonn.) Seeds and Their Inhibitory Activities on α-Glucosidase

With the bioactivity-guided method,a new flavanone glycoside,together with nine known flavonoids were isolated from 50% aqueous ethanol of litchi（Litchi chinensis Sonn.） seeds.The chemical structure of the new compound was elucidated via 1D and 2D nuclear magnetic resonance（NMR） techniques and mass spectrometry to be （2S）-pinocembrin-7-O-（6＂-O-α-L-arabinosyl-β-D-glucopyranoside）（1）,and the nine known compounds were determined to be quercetin（2）,phlorhizin（3）,pinocembrin-7-O-glucoside（4）,kaempferol-7-O-β-D-glucopyranoside（5）,onychin（6）,nairutin（7）,narcissin（8）,pinocembrin-7-O-[（6＂-O-β-D-glucopyranoside）-β-D-glucopyranoside]（9） and pinocembrin-7-O-[（2＂,6＂-di-O-α-L-rhamnopyranosyl）-β-D-glucopyranoside]（10）.Some of the isolated flavonoids were tested for their inhibitory effects on α-glucosidase.And compounds 2 and 3 showed stronger inhibitory activity than positive control.

Cloning and Sequence Analysis of Expansin Genes from Litchi chinensis Fruit

Using PCR degenerate primers, designed with reference to the sequences of the conserved amino acids of known expansins, to amplify cDNA fragments in litchi fruit by RT-PCR, two different cDNA fragments , named as Lc-Exp1 and Lc-Exp2 , were cloned. Lc-Exp1 and Lc-Exp2 was respectively composed of 531 bp encoding 177 amino acids and 537 bp encoding 179 amino acids. Eight cysteine residues and three tryp-tophan residues, which is supposed to be the characteristics of expansins, are conserved in both Lc-Exp1 and c-Exp2. In addition, the homology between the two expansins is 71. 6% at nucleotide acid sequences and 76.3% at amino acid sequences. The homology of Lc-Exp1 with Fa-Exp2 or Pp-Exp1 was 92.7% or 92.1%, but that of Lc-Exp2 with Fa-Exp2 or Pp-Exp1 was only 77. 4% or 76.3% at amino acid sequences.

Physiological Changes during the Process of Pericarp Browning in the Postharvest Litchi

[Objective] Pericarp browning in the postharvest litchi significantly reduced its commercial value and limited the expanding of litchi markets. Physiological changes during the process of pericarp browning were determined in order to identify the underlying mechanisms. [Method] Matured Feizixiao fruits were stored at 25 ℃ and 70%±5% relative humidity. The physiological changes happened in pericarp during storage were tested at an 8-hour interval. [Result] The fruit of Feizixiao (Litchi chinensis Sonn. cv Feizixiao) turned completely brown within 72 h after being harvested under the experimental conditions. Sharp increase of the browning index occurred from 48 to 64 hours after harvest (HAH). With the browning of pericarp,water content of the whole fruit and pericarp decreased continuingly. In contrast,there were no significant changes in the water content of pulp during the same period. MDA content,pH value and relative leakage rate of pericarp were increased during storage. Most of pigment contents including anthocyanin,flavonoid,phenols,chlorophyll a and total chlorophyll decreased. POD activity was initially increased in 32 HAH and then decreased afterwards. PPO activity was decreased continuously,while the activities of catalase and superoxide dismutase exhibited the pattern of 'increasing-decreasing-increasing' as the storage time progressed. Correlation,stepwise regression and path analyses showed that water loss of pericarp was the major factor of pericarp browning. Principal and cluster analyses showed that there were two stages of pericarp browning during the course of litchi storage. [Conclusion] Water status of pericarp was the most important factor affecting pericarp browning. The pericarp browning happened by stages,which was mainly determined by the water loss of pericarp.

Agrobacterium tumefaciens-mediated transformation of embryogenic callus and CRISPR/Cas9-mediated genome editing in‘Feizixiao'litchi

Litchi(Litchi chinensis Sonn.)is a type of commercially prevalent subtropical and tropical fruit.Since litchi has a highly heterozygous genetic background and a long reproductive cycle,conventional breeding methods(such as hybridization)have limited ability to nurture new litchi cultivars.Here,an efficient and stable Agrobacterium tumefaciens-mediated genetic transformation of embryogenic callus was established in‘Feizixiao’litchi.Transgenic materials were verified using polymerase chain reaction(PCR)analysis,β-glucuronidase(GUS)assay,and green fluorescent protein(GFP)assay.To implement the technology of the Clustered Regularly Interspaced Short Palindromic Repeats(CRISPR)/associated protein 9(CRISPR/Cas9)technology in‘Feizixiao’litchi and verify the validity of these transformation systems,the litchi polyphenol oxidase gene(LcPPO,JF926153)was knocked out.Various categories of mutations,covering base insertions,deletions,and substitutions,were found in transgenic materials via sequence analysis.The transformation system achieved high feasibility and efficiency,and the system of CRISPR/Cas9 was successfully employed to edit genes in‘Feizixiao’litchi.This work provides an essential foundation for investigating the functions of genes and accelerating litchi genetic improvement.

Effects of simulated acid rain on fertility of litchi

The regulatory role of calcium in fertility of pollen and pistil under simulated acid rain was investigated. The germination percentage of pollen treated with acid rain of pH 4.5 was 9.42% lower than that of control, and that of pH 3.5, pH 2.5 and pH 1.5 were 22.47%, 45.49% and 71.62%, respectively. Simultaneously, the injury character of pollen was obviously observed when flowers were treated with acid rain of pH 3.5. The difference in fruit setting rate between the female flower treated with acid rain of pH 4.0 and the control was significant at p 〈 0.05. Ca（NO3 ）5 of 0.2-0.4 mmol/L could promote pollen germination under the stress of acid rain. The beneficial function was reduced when calcium concentration surpassed 0.8 mmol/L. Spraying 2 mmol/L Ca（NO3 ）5 reduced the injury of acid rain to pistil and increased fruit-setting rate significantly. The physiological importance of calcium during pollen germination and pistil development was also discussed.

玉林市仙进奉荔枝高产栽培技术要点

为提升荔枝(Litchi chinensis Sonn.)果实的品质和产量,针对仙进奉荔枝在玉林市的物候期表现及果实变异的问题,主要从建园、种苗选择、秋梢培养、控梢促花、疏花保果、适时采摘、采后修剪及清园等方面描述其栽培技术要点,以期为仙进奉荔枝高质量生产提供参考。

荔枝中农药残留分布与膳食风险评估

调查中国非产地地区荔枝(Litchi chinensis Sonn.)的农药残留现状,在2022年从全国5个城市抽取荔枝样品100个批次,进行116种农药残留的检测,并对检出的农药品种进行农药残留膳食摄入风险评估。结果表明,荔枝中农药残留检出率为100%,农药残留合格率为37%;荔枝农药残留大部分位于果皮部位;通过清洗可以明显降低农药残留;检出的35种农药的%ADI在0%~1.17%,均远低于100%。荔枝的农药残留检出率和超标率较高,与农药最大残留限量值标准中规定检测部位为全果有关,但荔枝的膳食摄入风险较小,可放心食用。

荔枝、荔城和荔枝文化

荔枝(Litchi chinensis Sonn.)是莆田市树,莆田因其城内遍植荔枝树,所以有一个非常诗意的别称——荔城。在莆田,荔枝与百姓的日常生活有着千丝万缕的联系,荔枝融入到百姓的生活与民俗文化中,世代相传。荔枝、荔城与荔枝文化已融为一体。文章通过对荔枝景观风貌和"荔枝文化"内涵的探索与研究.

外源CPPU抑制‘妃子笑’荔枝果实着色过程的基因表达分析

为了探究花青苷和叶绿素相关结构基因与‘妃子笑’荔枝果皮着色的关系,本研究首先基于基因组数据鉴定了花青苷和叶绿素相关结构基因,然后分析了其在外源CPPU抑制‘妃子笑’荔枝着色过程的表达及对应酶活性。结果显示,花青苷合成关键酶UFGT,叶绿素降解途径NYC/NOL、MDcase以及PAO酶活性明显受到抑制,叶绿素合成途径CS和CAO及Chlase酶活性明显增加。转录组测序和RT-qPCR结果表明,外源CPPU显著抑制了花青苷合成途径结构基因LcPAL1、LcPAL3、LcC4H1、Lc4CL2、Lc4CL3、Lc4CL4、LcCHS2、LcCHS5、LcCHI、LcF3H/LcF3'H、LcDFR2、LcANS1、LcUFGT2、LcUFGT3,和叶绿素降解途径结构基因LcSGR2、LcPPH和LcPAO的表达;促进叶绿素合成相关途径基因LcHEMA、LcHEMD、LcCHLH1、LcCHLH2和LcCAO的表达,同时抑制转录因子基因LcMYB3、LcMYB4和LcWRKY3的表达。因此,推测外源CPPU可能通过抑制花青苷合成和叶绿素降解相关基因表达及酶活性,促进叶绿素合成相关基因的表达及酶活性,使‘妃子笑’荔枝果皮中花青苷与叶绿素比值在最佳可食期偏低而不能完全着色。研究结果为解决‘妃子笑’荔枝“滞绿”问题提供理论依据,也可为植物色泽问题的研究提供参考。

霜疫霉诱导的荔枝果皮几丁质酶活性及其基因表达分析

为探究荔枝果皮几丁质酶对霜疫霉病抗性中的功能,本研究以抗病品种‘黑叶’和感病品种‘桂味’为试验材料,分析荔枝果皮中的几丁质酶活性和基因表达情况。结果表明,果皮中几丁质酶活性不同,其与品种的抗病性正相关,霜疫霉菌侵染提高了果皮中酶活性。基于转录组数据,共检测到75条几丁质酶基因,在系统进化树上分为3枝。接种霜疫霉的抗病和感病品种果皮中差异表达基因有58条,表明几丁质酶基因响应霜疫霉入侵表达。不同进化分枝上的3个基因的表达水平因抗病性和接种时间的差异表达模式不同。LcChi3-1基因在抗病品种‘黑叶’中的表达水平远远高于感病品种‘桂味’,‘黑叶’果皮中LcChi3-1基因的表达水平与酶活性具有显著的相关性,表明其参与了对霜疫霉菌的抗病过程,并发挥主要作用。

基于转录组的荔枝PG基因家族鉴定及表达分析

本研究利用转录组数据对荔枝的PG基因家族进行分析,以探究PGs基因在荔枝中存在的形式,及荔枝PG基因家族在荔枝果实衰老中的作用及表达规律。结果表明,(1)荔枝中存在21个PG基因家族成员,它们的理化性质差异较大,多数蛋白表现为酸性及亲水性,位于细胞外基质或细胞质膜上。(2)该基因家族成员都存在保守基序8和保守基序14,结构域SPNTDG(Ⅰ)、GDDC(Ⅱ)和RIK(Ⅳ),但缺失了结构域CGPGHG(Ⅲ)。(3)进化树显示该基因家族成员分为5个类群,其中GroupⅢ是主要类群,其他类群在进化过程中逐渐形成。(4)RT-qPCR结果表明该基因家族的蛋白在荔枝生长发育过程中发挥不同作用,研究发现PG3、PG12、PG15、PG21与果实的衰老有关,表达量随果实衰老进程加剧而不断升高,它们正向调控了果实的衰老。本研究初步探究了PG基因家族成员在荔枝果实衰老过程中的作用,找出了几个和果实衰老相关的PG基因,为进一步研究荔枝的生理提供参考。

基于转录组的荔枝PAL基因家族鉴定及表达分析

本研究通过运用荔枝采后褐变的转录组数据,运用生物信息学的方法对荔枝PAL基因家族进行鉴定,然后分析其理化性质、蛋白的各级结构、保守基序、与其他物种的进化关系及荔枝采后室温下褐变的基因表达模式。结果表明,共在荔枝中鉴定出4个具有PLN02457结构域的PAL基因。其蛋白质的长度为706~724个氨基酸,分子质量在39.990~43.759 kD,理论等电点存在于6.03~6.34之间,不稳定系数介于29.61~38.10,脂肪指数在88.87~93.40。各蛋白的α-螺旋介于54.72%~59.35%,无规则卷曲在30%左右,两者在二级结构中占比相对较高。4个荔枝PAL基因蛋白均存在MIO保守结构域,该结构域普遍存在于PAL基因家族蛋白中。4个荔枝PAL基因蛋白均存在PAL基因家族蛋白普遍出现的MIO保守结构域。通过多物种进化树分析发现荔枝与双子叶植物PAL基因家族的亲缘关系是相对较近的。4个荔枝PAL基因在室温下采后荔枝果皮发生褐变的过程中都展现了不同的表达模式。本研究发现了LcPAL2和LcPAL3 2个基因和PAL活性与荔枝果皮褐变有着很密切的联系,为进一步挖掘荔枝PAL基因功能提供了参考。