Expression and organisation of antenna proteins in the light-and temperature-sensitive barley mutant chlorina-104
Expression and organisation of antenna proteins in the light-and temperature-sensitive barley mutant chlorina-104
复制标题
光和温度敏感的大麦突变体 Chlorina-104 中天线蛋白的表达和组织
作者：
J. Knoetzel;D. Simpson
大麦（Hordeum vulgare L.）当在高辐射下，特别是在低温下生长时，叶绿素缺乏。Chlorina-104叶绿体的类囊体比野生型少，贴伏叶片比非贴伏叶片少。冷冻断裂的超微结构显示，从堆叠的类囊体区（PFs）的原生质断裂面的颗粒的损失，与大部分的捕光复合物（LHC）II的损失一致，和一些大颗粒的损失，从同一面的未堆叠的类囊体区（PFu），表明光系统-I颗粒的损失。突变体是显着的高密度的颗粒上的外质骨折面的未堆积类囊体区（EFu），其水平下降到正常后，转移到低光。叶绿素缺乏主要是由于LHCII和LHCI-680的损失，随之而来的是大量叶绿素（Chl）B和叶黄素新黄素和叶黄素的损失。识别LHCI-680的23-kDa多肽的单克隆抗体的使用证实，在限制性条件下生长的chlorina-104的叶绿体中，LHCI-680严重耗尽。77 K荧光发射光谱的特征是在720 nm处有一个明显的肩峰，该肩峰来自光系统I反应中心（CPI）。由于CPI的荧光通常被LHCI-730淬灭，这表明LHCI-680介导LHCI-730和反应中心之间的激发能量转移。将幼苗移至允许条件后，LHCII和LHCI-680开始在褪绿叶片中积累，并且荧光发射光谱类似于野生型叶片。用特异性Cab探针测量稳态mRNA水平，显示野生型和突变体之间没有差异，表明LHCII和LHCI-680积累的控制是在转录后水平。
The nuclear gene mutant chlorina-104 of barley (Hordeum vulgare L.) is chlorophyll-deficient when grown under high irradiance, particularly at low temperatures. Chlorina-104 chloroplasts had fewer thylakoids than the wild type, and fewer appressed lamellae relative to non-appressed lamellae. The freeze-fracture ultrastructure showed a loss of particles from the protoplasmic fracture face of the stacked thylakoid region (PFs), consistent with the loss of most of the light-harvesting complex (LHC) II, and a loss of some of the large particles from the same face of the unstacked thylakoid region (PFu), indicating a loss of photosystem-I particles. The mutant is remarkable for the high density of particles on the exoplasmic fracture face of the unstacked thylakoid region (EFu), levels of which fell to normal after transfer to low light. The chlorophyll deficiency was shown to be primarily caused by the loss of LHCII and LHCI-680, with the consequent loss of much of the chlorophyll (Chl) b and the xanthophylls neoxanthin and lutein. The use of a monoclonal antibody which recognises the 23-kDa polypeptide of LHCI-680, confirmed that it was severely depleted in chloroplasts from chlorina-104 grown under restrictive conditions. The 77 K fluorescence emission spectrum was characterised by a pronounced shoulder at 720 nm, arising from the photosystem-I reaction centre (CPI). Since fluorescence from CPI is normally quenched by LHCI-730, this indicates that LHCI-680 mediates excitation energy transfer between LHCI-730 and the reaction centre. After moving seedlings to permissive conditions, LHCII and LHCI-680 began to accumulate in the chlorotic leaves and the fluorescence emission spectrum resembled that of wild-type leaves. Measurement of the steady-state mRNA levels with specific Cab probes, showed no difference between wild type and mutant, indicating that control of LHCII and LHCI-680 accumulation was at a post-transcriptional level.
影响因子：
2.9
作者：
FLING, SP;GREGERSON, DS
通讯作者：
GREGERSON, DS
DOI：
10.1073/pnas.84.24.8844
发表时间：
1987-12-01
影响因子：
11.1
作者：
HOFFMAN, NE;PICHERSKY, E;CASHMORE, AR
通讯作者：
CASHMORE, AR