Shi Yun, Jiang Li, Zhang Li, Kang Ruoyi, Yu Zhifang
College of Food Science and Technology, Nanjing Agricultural University , Nanjing 210095, China.
Suzhou Academy of Agriculture , Suzhou 215155, China.
Hortic Res. 2014 Jan 22;1:6. doi: 10.1038/hortres.2014.6. eCollection 2014.
A proteomic study, using two-dimensional polyacrylamide gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight/time-of-flight, was conducted in apple fruit (cv. 'Golden Delicious') starting at 10 days prior to harvest through 50 days in storage. Total protein was extracted using a phenol/sodium dodecyl sulfate protocol. More than 400 protein spots were detected in each gel and 55 differentially expressed proteins (p<0.05) were subjected to matrix-assisted laser desorption/ionization time-of-flight/time-of-flight analysis. Fifty-three of these proteins were finally identified using an apple expressed sequence tag database downloaded from Genome Database for Rosaceae and placed into six categories. The categories and the percentage of proteins placed in each category were stress response and defense (49.0%), energy and metabolism (34.0%), fruit ripening and senescence (5.6%), signal transduction (3.8%), cell structure (3.8%) and protein synthesis (3.8%). Proteins involved in several multiple metabolic pathways, including glycolysis, pentose-phosphate pathway, anti-oxidative systems, photosynthesis and cell wall synthesis, were downregulated, especially during the climacteric burst in respiration and during the senescent stages of fruit development. Proteins classified as allergens or involved in cell wall degradation were upregulated during the ripening process. Some protein spots exhibited a mixed pattern (increasing to maximal abundance followed by a decrease), such as 1-aminocyclopropane-1-carboxylate oxidase, L-ascorbate peroxidase and abscisic acid response proteins. The identification of differentially expressed proteins associated with physiological processes identified in the current study provides a baseline of information for understanding the metabolic processes and regulatory mechanisms that occur in climacteric apple fruit during ripening and senescence.
采用二维聚丙烯酰胺凝胶电泳和基质辅助激光解吸/电离飞行时间/飞行时间质谱技术，对苹果果实（品种为“金冠”）从收获前10天到贮藏50天进行了蛋白质组学研究。使用苯酚/十二烷基硫酸钠法提取总蛋白。每张凝胶上检测到400多个蛋白点，对55个差异表达蛋白（p<0.05）进行了基质辅助激光解吸/电离飞行时间/飞行时间质谱分析。最终利用从蔷薇科基因组数据库下载的苹果表达序列标签数据库鉴定出其中53个蛋白，并将其分为六类。各类别及其所含蛋白的百分比分别为应激反应和防御（49.0%）、能量和代谢（34.0%）、果实成熟和衰老（5.6%）、信号转导（3.8%）、细胞结构（3.8%）和蛋白质合成（3.8%）。参与多种代谢途径（包括糖酵解、戊糖磷酸途径、抗氧化系统、光合作用和细胞壁合成）的蛋白质表达下调，尤其是在呼吸跃变期和果实发育的衰老阶段。在成熟过程中，被归类为过敏原或参与细胞壁降解的蛋白质表达上调。一些蛋白点呈现出混合模式（先增加到最大丰度然后下降），如1-氨基环丙烷-1-羧酸氧化酶、L-抗坏血酸过氧化物酶和脱落酸应答蛋白。本研究中鉴定出的与生理过程相关的差异表达蛋白，为理解跃变型苹果果实在成熟和衰老过程中发生的代谢过程和调控机制提供了信息基线。
