Die Jose V, Arora Rajeev, Rowland Lisa J
Agricultural Research Service, U.S. Department of Agriculture, Beltsville, Maryland, United States of America.
Department of Horticulture, Iowa State University, Ames, Iowa, United States of America.
PLoS One. 2017 May 23;12(5):e0177389. doi: 10.1371/journal.pone.0177389. eCollection 2017.
To gain a better understanding of cold acclimation in rhododendron and in woody perennials in general, we used the 2D-DIGE technique to analyze the rhododendron proteome during the seasonal development of freezing tolerance. We selected two species varying in their cold acclimation ability as well as their thermonasty response (folding of leaves in response to low temperature). Proteins were extracted from leaves of non-acclimated (NA) and cold acclimated (CA) plants of the hardier thermonastic species, R. catawbiense (Cata.), and from leaves of cold acclimated plants of the less hardy, non-thermonastic R. ponticum (Pont.). All three protein samples (Cata.NA, Cata.CA, and Pont.CA) were labeled with different CyDyes and separated together on a single gel. Triplicate gels were run and protein profiles were compared resulting in the identification of 72 protein spots that consistently had different abundances in at least one pair-wise comparison. From the 72 differential spots, we chose 56 spots to excise and characterize further by mass spectrometry (MS). Changes in the proteome associated with the seasonal development of cold acclimation were identified from the Cata.CA-Cata.NA comparisons. Differentially abundant proteins associated with the acquisition of superior freezing tolerance and with the thermonastic response were identified from the Cata.CA-Pont.CA comparisons. Our results indicate that cold acclimation in rhododendron involves increases in abundance of several proteins related to stress (freezing/desiccation tolerance), energy and carbohydrate metabolism, regulation/signaling, secondary metabolism (possibly involving cell wall remodeling), and permeability of the cell membrane. Cold acclimation also involves decreases in abundance of several proteins involved in photosynthesis. Differences in freezing tolerance between genotypes can probably be attributed to observed differences in levels of proteins involved in these functions. Also differences in freezing tolerance may be attributed to higher levels of some constitutive protective proteins in Cata. than in Pont. that may be required to overcome freeze damage, such as glutathione peroxidase, glutamine synthetase, and a plastid-lipid-associated protein.
为了更好地理解杜鹃花以及一般木本多年生植物的冷驯化过程,我们使用二维差异凝胶电泳(2D-DIGE)技术分析了耐寒性季节性发育过程中的杜鹃花蛋白质组。我们选择了两种在冷驯化能力以及感热性反应(叶片因低温而折叠)方面存在差异的物种。从更耐寒且有感热性的卡托巴杜鹃(R. catawbiense,简称Cata.)的未驯化(NA)和冷驯化(CA)植株的叶片中提取蛋白质,以及从不太耐寒且无感热性的南欧杜鹃(R. ponticum,简称Pont.)的冷驯化植株的叶片中提取蛋白质。所有三个蛋白质样品(Cata.NA、Cata.CA和Pont.CA)用不同的CyDye进行标记,并在同一块凝胶上一起分离。进行了三次重复凝胶电泳,并比较蛋白质图谱,结果鉴定出72个蛋白质点,这些蛋白质点在至少一对比较中始终具有不同的丰度。从这72个差异点中,我们选择了56个点进行切除,并通过质谱(MS)进一步表征。从Cata.CA - Cata.NA比较中鉴定出与冷驯化季节性发育相关的蛋白质组变化。从Cata.CA - Pont.CA比较中鉴定出与获得卓越耐寒性以及感热性反应相关的差异丰度蛋白质。我们的结果表明,杜鹃花的冷驯化涉及几种与胁迫(耐冻性/耐干性)、能量和碳水化合物代谢、调节/信号传导、次生代谢(可能涉及细胞壁重塑)以及细胞膜通透性相关的蛋白质丰度增加。冷驯化还涉及几种参与光合作用的蛋白质丰度降低。基因型之间耐寒性的差异可能归因于这些功能相关蛋白质水平的观察差异。耐寒性的差异也可能归因于Cata.中一些组成型保护蛋白的水平高于Pont.,这些蛋白可能是克服冻害所必需的,如谷胱甘肽过氧化物酶、谷氨酰胺合成酶和一种质体 - 脂质相关蛋白。