iTRAQ‐Based Proteomics Reveals that the Tomato ms1035 Gene Causes Male Sterility through Compromising Fat Acid Metabolism

So far, over 50 spontaneous male sterile mutants of tomato have been described and most of them are categorized as genetic male sterility. To date, the mechanism of tomato genetic male sterility remained unclear. In this study, differential proteomic analysis is performed between genetic male sterile line (2‐517), which carries the male sterility (ms10³⁵) gene, and its wild‐type (VF‐11) using isobaric tags for relative and absolute quantification‐based strategy. A total of 8272 proteins are quantified in the 2–517 and VF‐11 lines at the floral bud and florescence stages. These proteins are involved in different cellular and metabolic processes, which express obvious functional tendencies toward the hydroxylation of the ω‐carbon in fatty acids, the tricarboxylic acid cycle, the glycolytic, and pentose phosphate pathways. Based on the results, a protein network explaining the mechanisms of tomato genetic male sterility is proposed, finding the compromising fat acid metabolism may cause the male sterility. These results are confirmed by parallel reaction monitoring, quantitative Real‐time PCR (qRT‐PCR), and physiological assays. Taken together, these results provide new insights into the metabolic pathway of anther abortion induced by ms10³⁵ and offer useful clues to identify the crucial proteins involved in genetic male sterility in tomato.     

河西走廊不同产地‘赤霞珠’酿酒葡萄果实品质评价

为了确定河西走廊地区‘赤霞珠’酿酒葡萄核心品质指标,建立‘赤霞珠’酿酒葡萄品质综合评价模型。从张掖、武威、嘉峪关3个酿酒葡萄主产市的代表性果园采集6份‘赤霞珠’葡萄样品进行品质测定,通过主成分分析和聚类分析法确定‘赤霞珠’葡萄核心品质指标,运用层次分析法确定指标权重并建立‘赤霞珠’葡萄品质综合评价模型。结果表明:(1)不同产地‘赤霞珠’酿酒葡萄品质指标存在明显差异性,张掖市国风葡萄酒庄园的‘赤霞珠’葡萄果糖、蔗糖、草酸、柠檬酸含量均高于其他地区,且可溶性固形物、可溶性糖、总酚、苹果酸含量在各产地中也均保持在最高水平。(2)相关性分析发现,葡萄果实葡萄糖含量与可溶性固形物含量、果糖与可溶性糖含量之间呈极显著正相关,固酸比和糖酸比均与可滴定酸含量呈极显著负相关关系。(3)综合主成分分析、聚类分析和相关性分析结果,确定维生素C(Vc)、单宁、果糖和固酸比是‘赤霞珠’葡萄核心品质指标,应用层次分析法建立了‘赤霞珠’葡萄品质综合评价模型为Y=0.0960×Vc含量+0.1611×单宁含量+0.2771×果糖含量+0.4568×固酸比(各指标含量均经过标准化处理)。研究发现,河西走廊地区‘赤霞珠’葡萄果实品质最佳产地是张掖市,果实Vc、单宁、果糖和固酸比是‘赤霞珠’葡萄的核心品质指标,以其建立的评价模型可用于‘赤霞珠’葡萄品质的综合评价。     

Synthesis of acyl thiourea derivatives of chitosan and their antimicrobial activities in vitro

Three different acyl thiourea derivatives of chitosan (CS) were synthesized and their structures were characterized by FT-IR spectroscopy and elemental analysis. The antimicrobial behaviors of CS and its derivatives against four species of bacteria (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Sarcina) and four crop-threatening pathogenic fungi (Alternaria solani, Fusarium oxysporum f. sp. vasinfectum, Colletotrichum gloeosporioides (Penz.) Saec, and Phyllisticta zingiberi) were investigated. The results indicated that the antimicrobial activities of the acyl thiourea derivatives are much better than that of the parent CS. The minimum value of MIC and MBC of the derivatives against E. coli was 15.62 and 62.49 microg/mL, respectively. All of the acyl thiourea derivatives had a significant inhibitory effect on the fungi in concentrations of 50-500 microg/mL; the maximum inhibitory index was 66.67%. The antifungal activities of the chloracetyl thiourea derivatives of CS are noticeably higher than the acetyl and benzoyl thiourea derivatives. The degree of grafting of the acyl thiourea group in the derivatives was related to antifungal activity; higher substitution resulted in stronger antifungal activity.     

Progressive Degradation of Crude Oil n-Alkanes Coupled to Methane Production under Mesophilic and Thermophilic Conditions

Although methanogenic degradation of hydrocarbons has become a well-known process, little is known about which crude oil tend to be degraded at different temperatures and how the microbial community is responded. In this study, we assessed the methanogenic crude oil degradation capacity of oily sludge microbes enriched from the Shengli oilfield under mesophilic and thermophilic conditions. The microbial communities were investigated by terminal restriction fragment length polymorphism (T-RFLP) analysis of 16S rRNA genes combined with cloning and sequencing. Enrichment incubation demonstrated the microbial oxidation of crude oil coupled to methane production at 35 and 55°C, which generated 3.7±0.3 and 2.8±0.3 mmol of methane per gram oil, respectively. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that crude oil n-alkanes were obviously degraded, and high molecular weight n-alkanes were preferentially removed over relatively shorter-chain n-alkanes. Phylogenetic analysis revealed the concurrence of acetoclastic Methanosaeta and hydrogenotrophic methanogens but different methanogenic community structures under the two temperature conditions. Candidate divisions of JS1 and WWE 1, Proteobacteria (mainly consisting of Syntrophaceae, Desulfobacteraceae and Syntrophorhabdus) and Firmicutes (mainly consisting of Desulfotomaculum) were supposed to be involved with n-alkane degradation in the mesophilic conditions. By contrast, the different bacterial phylotypes affiliated with Caldisericales, “Shengli Cluster” and Synergistetes dominated the thermophilic consortium, which was most likely to be associated with thermophilic crude oil degradation. This study revealed that the oily sludge in Shengli oilfield harbors diverse uncultured microbes with great potential in methanogenic crude oil degradation over a wide temperature range, which extend our previous understanding of methanogenic degradation of crude oil alkanes.     

不同分子量γ-聚谷氨酸的生物合成

【背景】不同分子量的γ-聚谷氨酸在农业、化妆品和医药领域具有重要的应用价值,开发不同分子量γ-聚谷氨酸的生物合成工艺已成为研究热点。【目的】在γ-聚谷氨酸生产菌株枯草芽孢杆菌(Bacillus subtilis) KH2中实现不同分子量γ-聚谷氨酸的合成。【方法】分别克隆表达不同来源的水解酶,包括B.subtilis来源的γ-聚谷氨酸水解酶PgdS和YwtE,以及地衣芽孢杆菌来源的SGH。研究不同来源水解酶对B. subtilis KH2产γ-聚谷氨酸分子量的影响。通过改变水解酶处理条件获得不同分子量γ-聚谷氨酸的生物合成工艺。【结果】PgdS、YwtE和SGH均可降低γ-聚谷氨酸的分子量,其中PgdS水解效果最好,可以将γ-聚谷氨酸分子量由原来的1 600 kDa降低为180 kDa。通过优化PgdS的添加量与添加时间,在B. subtilis KH2中获得了分子量为210–600 kDa的γ-聚谷氨酸。【结论】利用水解酶处理,可以在B. subtilis KH2中实现不同分子量γ-聚谷氨酸的生物合成。该方法反应条件温和、分子量可控区间宽,具有良好的应用前景。     

Wheat genomic study for genetic improvement of traits in China

Science China Life Sciences - Bread wheat (Triticum aestivum L.) is a major crop that feeds 40% of the world’s population. Over the past several decades, advances in genomics have led to...     

番茄幼苗盐胁迫响应蛋白质组分析

采用营养液栽培,以盐敏感型番茄品种M82为试材,利用双向电泳(2-DE)研究盐胁迫处理下幼苗叶片蛋白质的表达谱,并采用基质辅助激光解析飞行时间串联质谱(MALDI-TOF/TOF-MS)技术进行差异蛋白质的分离及质谱鉴定。结果表明:(1)盐胁迫处理下,利用2-DE获得差异显著蛋白点20个,其中17个蛋白质点丰度上调表达,3个蛋白质点丰度下调表达。(2)通过质谱分析和蛋白质NCBInr数据库检索,共鉴定出19个差异蛋白,分别为果糖-二磷酸醛缩酶、S-腺苷甲硫氨酸合成酶、甘油醛-3-磷酸脱氢酶等及3个功能未知蛋白;这些鉴定出的差异蛋白质与能量代谢、光合作用、蛋白合成、氧化还原平衡等过程相关,暗示所分离鉴定的蛋白可能参与了番茄的盐胁迫响应,为进一步研究番茄抗逆机制奠定基础。     

华北山区典型人工林土壤水势动态和水分运移规律

大规模植树造林工程有效缓解了我国北方水土流失等问题,但伴随植被生长和降水格局变化,水循环过程发生明显改变。土壤水分运动是水循环的关键过程,研究变化环境下人工林植被土壤水分运移规律,对植被生态恢复具有重要意义。基于2014-2018年多时间尺度（半小时、天、月和年）华北山区崇陵流域典型人工侧柏林和荒草土壤剖面水势监测数据,阐明不同植被覆盖下土水势动态变化规律,提出土壤水分运移和植被水分利用模式。研究结果表明：侧柏林土壤水势日变幅显著低于荒草植被,但土水势日变幅随土壤深度增加而减小的速率90 a侧柏依次大于60 a侧柏和荒草;月、年尺度侧柏林不同深度土水势变化对降水的响应大于荒草地,其中60 a侧柏林年均土水势与年降雨量显著线性相关（P<0.05）。由水势梯度和零通量面多年平均变化可知,90 a侧柏林0-50 cm土壤水呈下渗趋势,根系水力提升促使50-100 cm土壤水向上蒸散;60 a侧柏林0-20 cm、70-100 cm以及枯水年30-70 cm土壤水均以蒸散为主,根系可同时吸收利用表层和深层土壤水分;荒草地0-20 cm土壤水分蒸发强烈,且为根系主要吸水深度,20-100 cm土壤水稳定下渗。相比60 a侧柏林和荒草,90 a侧柏林的土壤调蓄能力增强,与荒草互被可减少植被间水分竞争,充分利用土壤水,从而减少流域内地表径流和土壤侵蚀量。