高等植物K+吸收机制研究进展

从高亲和性和低亲和性K⁺吸收两个方面较详细介绍了K⁺营养的吸收机制。高亲和性K⁺吸收机制包括H⁺-K⁺交换ATPase、K⁺-ATPase、H⁺-K⁺ symporter和Na⁺-K⁺ symporter;低亲和性K⁺吸收机制也被称为“协助扩散”,研究表明是通过K⁺通道进行的,但K⁺通道的确切结构尚无定论。综述了植物K⁺吸收的调节,并对相关问题进行了展望。     

Function Analysis of Sucrose Transporter OsSUT4 in Sucrose Transport in Rice

【Objective】The transmembrane transport of sucrose is mainly mediated by sucrose transporters, among which five SUT coding genes have been identified in rice. However, the role of OsSUT4 in the sucrose transport is unclear. 【Method】CRISPR/Cas9 techniques were used to construct ossut4-deleted mutants. The ossut4 mutant was featured by lower plant height and grain yield as well as higher tiller number as compared with wild type plants.【Result】Sucrose and starch accumulation in the leaf of the ossut4 mutants lead to slower net photosynthetic rate; insufficient sugar supply results in the postpone of grain filling. Base on the subcellular and histochemical localization, OsSUT4 was located on the cytoplasmic membrane. Tissue localization showed that OsSUT4 was expressed in the embryo of germinating seed, vascular bundles of coleoptile, glume shell, anthers at flowering stage and aleurone layer of caryopsis at filling stage. 【Conclusion】OsSUT4 plays an important role in sucrose transport.     

磷肥和有机肥对白菜产量及土壤磷库的影响（征文）

采用2年的微区筒定位试验研究了磷肥和有机肥对白菜产量、白菜全磷、土壤全磷、有机磷、Olsen-P、水溶性磷及生物有效磷等的影响。结果表明，磷肥用量150～600 mg·kg-1土，白菜产量增加14.9%~21.5%； 有机肥用量33.3～133.2 g·kg-1土，白菜产量增加18.2%~25.9%；施用150、300、600 mg·kg-1磷肥和施用33.3、66.6、133.2 g·kg-1有机肥及施用有机肥基础上增施磷肥，白菜产量均无显著变化。施用磷肥和有机肥显著增加白菜的全磷量，大量施用磷肥和有机肥导致白菜对磷的奢侈吸收。随磷肥和有机肥用量的增加，土壤Olsen-P、水溶性磷、生物有效磷均显著增加；随有机肥用量的增加土壤有机磷显著增加。土壤Olsen-P与水溶性磷和生物有效磷呈显著正相关，与土壤有机磷无显著相关性。     

钝顶螺旋藻营养生理的研究Ⅲ.钝顶螺旋藻对磷酸盐的吸收利用

利用均匀设计法设计得到的１２种培养基及对照Ｚａｒｒｏｕｋ培养基对钝顶螺旋藻Ｓｐｉｒｕｌｉｎａ ｐｌａｔｅｎｓｉｓ）Ｓ６品系进行培养,研究了添加磷酸盐的不同培养基下螺旋藻对磷酸盐的吸收利用。结果表明,螺旋藻Ｓ６磷酸盐的净利用在０．２０～０．８６ｍｍｏｌ／Ｌ之间,且与螺旋藻生长速度呈线性关系;磷酸盐为螺旋藻生长利用的主要磷源,含量不足会限制螺旋藻的正常生长;培养基中的磷酸盐添加量以１．１６ｍｍｏｌ／Ｌ左右最为适宜,既可满足藻体的最佳生长,又可降低约６０％的磷源养殖成本。     

Effect of fish meal replacement by plant protein blend on amino acid concentration,transportation and metabolism in juvenile turbot (Scophthalmus maximus L.)

The objective of the study was to evaluate the effects of incorporating plant protein blend in juvenile turbot (Scophthalmus maximus L.) diet on free amino acid (AA) concentration and the expression of genes related to peptide and AA transporters, key enzymes of AA metabolism and AA response (AAR) pathway. Fish were fed diets with fish meal (FM), or 400 g/kg FM replacement by plant protein blend for 9 weeks. Compared with the FM diet, PP40 diet did not affect plasma essential amino acid (EAA) concentration or AA metabolic enzymes gene in intestine, while it significantly upregulated all the detected peptide and neutral AA transporters gene. Results in muscle indicated that PP40 diet led to a great reduction of EAA concentrations and mRNA abundance of two kinds of AA transporters (SNAT2 and b^0,+AT), while it greatly increased the gene expression of L‐type and T‐type AA transporters (LAT2 and TAT1) and the enzymes of AA catabolism (BCKDH‐E2) and anabolism (asparagine synthetase). In addition, the expression of genes related to AAR pathway were all greatly stimulated by PP40 diet in muscle. Our results provide a molecular explanation for the change of tissues AA concentrations caused by plant protein in turbot, which maybe applicable for general carnivorous fish.     

急性盐度胁迫对日本黄姑鱼肌肉组织转录组的影响

盐度是影响鱼类各种生理活动的重要环境因素,为探讨急性盐度胁迫对经济海水鱼类日本黄姑鱼基因表达水平的影响,实验基于Illumina HiSeq^TM 2500高通量测序平台,对不同盐度条件下日本黄姑鱼幼鱼肌肉组织进行转录组测序并开展生物信息学分析。结果显示,高盐组、低盐组和对照组分别获得46 379 598、36 130 844和38 715 820条Clean reads,总碱基数分别为5.27、4.87和5.53 GB。经组装得到91 667条转录本,去冗余后拼接得到61 601条Unigenes。与对照组相比,高盐组和低盐组分别有2 230和1 377个差异Unigene上调,1 959和2 447个差异Unigene下调,随机选取6条差异表达基因进行实时荧光定量PCR验证,结果与转录组测序一致。通过对显著差异表达基因进行筛选,在高盐组和低盐组中分别发现21和41个差异表达基因与离子通道相关,共有的离子通道相关基因为15个,其中14个基因表达趋势一致。而在高盐组和低盐组发现的离子转运体基因分别为6和10个。GO功能富集分析发现,差异基因显著富集在蛋白酶体、补体激...     

Effects of phosphate fertilizer levels on cowpea pod-sucking bug populations and damage

The effect of different application levels of phosphate fertilizer on cowpea pod-sucking bugs [Clavigralla sp., Riptortus sp., Anoplocnemis., Mirperus sp. and Negara sp. (Heteroptera)] was studied using 0 (control), 20, 40 and 60 kg/ha of single super-phosphate. The results showed that the bug densities decreased significantly with increase in rate of application. At 40 and 60 kg/ha, grain yields were significantly higher than at the lower rates of application. Crude protein, fibre, oxalate, phytin, potassium and magnesium contents as well as seed hardness also increased with increase in the rate of fertilizer application.     

Role of apolipoprotein E in cholesterol efflux mediated by ABCA1 and ABCG1

AIM:To investigate the role of apolipoprotein E(ApoE) in cholesterol efflux mediated by ATP-binding cassette transporter A1(ABCA1) and ATP-binding cassette transporter G1(ABCG1). METHODS:RAW 264.7 cells were seeded in either 6-well or 24-well plates, and then incubated with 20 mg/L low-density lipoprotein receptor gene knockout(LDLr^-/-) mouse lipoprotein 20 mg/L ApoE gene knockout(ApoE^-/-) mouse lipoprotein or culture medium alone. The changes of intracellular lipid content were measured by transmission electron microscopy and enzymatic colorimetric method. The cholesterol efflux was determined by liquid scintillation. The mRNA and protein levels of ABCA1 and ABCG1 were detected by real-time PCR and Western blotting, respectively. RESULTS:The ApoE^-/- mouse lipoprotein increased the content of intracellular cholesterol ester by 60% compared with the control cells. In addition, ApoE^-/- mouse lipoprotein treatment decreased the cholesterol efflux to apolipoprotein A-I(ApoA-I) and high-density lipoprotein(HDL) compared with LDLr^-/- mouse lipoprotein treatment. ApoE^-/- mouse lipoprotein treatment inhibited the mRNA and protein levels of ABCA1 and ABCG1 compared with LDLr^-/- mouse lipoprotein treatment. CONCLUSION:Apolipoprotein E plays an important role in the cholesterol efflux of macrophages, which is associated with its regulatory effect on the expression of ABCA1 and ABCG1.     

Effect of ginsenoside Rb1 on proliferation and serotonin transporter and 5-HT1B R expression in hypoxia-induced rat pulmonary artery smooth muscle cells via Rho/Rho-kinase pathway

AIM: To observe the effect of ginsenoside Rb1 on the proliferation and the expression of serotonin transporter (SERT), 5-hydroxytryptamine 1B receptor (5HT_1BR) in rat pulmonary artery smooth muscle cells (PASMCs) under hypoxia condition and the relationship with Rho/Rho-kinase signal pathway.METHODS: PASMCs were isolated from the adult male SD rats and primarily cultured. The subcultured cells from the 4th generation to the 6th generation were harvested and divided into normal group, and hypoxia group, different concentrations of Rb1 incubation groups treated with 50, 100 and 200 mg/L ginsenoside Rb1 under hypoxia (HR50, HR100 and HR200 groups, respectively). The viability of the PASMCs was measured by CCK-8 assay. BrdU positive cells were determined using flow cytometry. The expression of serotonin transporter and 5HT_1BR at mRNA and protein levels was detected by RT-PCR and Western blot, respectively. The PASMCs were randomly divided into normal group, hypoxia group, HR200 group and hypoxia+Y-27632 incubation group (HY group). The mRNA expression of Rho-kinase and phosphorylated myosin phosphatase target subunit 1 (p-MYPT1) protein level were investigated by RT-PCR and Western blot, respectively.RESULTS: Compared with normal group, the proliferation of PASMCs in hypoxia group was significantly increased (P<0.01). The cell viability and the expression of SERT and 5HT_1BR at mRNA and protein levels in all different concentrations of Rb1 groups were obviously decreased compared with hypoxia group (P<0.05). The mRNA expression of Rho-kinase and protein level of p-MYPT1 were markedly decreased in HR200 group, and no significant difference compared with HY group was observed (P<0.01).CONCLUSION: Treatment with ginsenoside Rb1 might prevent hypoxia-induced proliferation of PASMCs and over-expression of SERT and 5HT_1BR through inhibiting the Rho/Rho-kinase pathway.