Chloroplasts are semi-autonomous organelles, with more than 95% of their proteins encoded by the nuclear genome. The chloroplast-to-nucleus retrograde signals are critical for the nucleus to coordinate its gene expression for optimizing or repairing chloroplast functions in response to changing environments. In chloroplasts, the pentatricopeptide-repeat protein GENOMES UNCOUPLED 1 (GUN1) is a master switch that senses aberrant physiological states, such as the photooxidative stress induced by norflurazon (NF) treatment, and represses the expression of photosynthesis-associated nuclear genes (PhANGs). However, it is largely unknown how the retrograde signal is transmitted beyond GUN1. In this study, a protein GUN1-INTERACTING PROTEIN 1 (GIP1), encoded by At3g53630, was identified to interact with GUN1 by different approaches. We demonstrated that GIP1 has both cytosol and chloroplast localizations, and its abundance in chloroplasts is enhanced by NF treatment with the presence of GUN1. Our results suggest that GIP1 and GUN1 may function antagonistically in the retrograde signaling pathway.
植物在自然界中面临各种环境侵害时候,如干旱、盐、低温和病菌袭击,会启动自身的抵御机制来适应各种侵害。蔗糖非发酵相关的蛋白激酶(sucrose non-fermenting-1-related protein kinase,SnRK)是广泛存在于植物中的一类Ser/Thr蛋白激酶,参与各种胁迫信号传导通路,对植物抵御不良环境起到重要作用。植物中蔗糖非发酵相关的蛋白激酶共有38个成员,可以分为3个亚家族:SnRK1、SnRK2和SnRK3。本文主要讨论SnRK家族的研究进展,揭示SnRK家族在植物抗逆中的重要作用。 相似文献
Human rabies cases in the Guangxi province of China decreased from 839 in 1982 to 24 in 1995, but subsequently underwent a sharp increase, and has since maintained a high level.
Methodology/Principal Findings
3,040 brain samples from normal dogs and cats were collected from 14 districts of Guangxi and assessed by RT-PCR. The brain samples showed an average rabies virus (RV) positivity rate of 3.26%, but reached 4.71% for the period Apr 2002 to Dec 2003. A total of 30 isolates were obtained from normal dogs and 28 isolates from rabid animals by the mouse inoculation test (MIT). Six representative group I and II RV isolates showed an LD50 of 10−5.35/ml to 10−6.19/ml. The reactivity of monoclonal antibodies (MAbs) to group I and II RV isolates from the Guangxi major epidemic showed that eight anti-G MAbs showed strong reactivity with isolates of group I and II with titers of ≥10,000; however, the MAbs 9-6, 13-3 and 12-14 showed lower reactivity. Phylogenetic analysis based on the G gene demonstrated that the Guangxi RV isolates have similar topologies with strong bootstrap values and are closely bonded. Alignment of deduced amino acids revealed that the mature G protein has four substitutions A96S, L132F, N436S, and A447I specific to group I, and 13 substitutions T90M, Y168C, S204G, T249I, P253S, S289T, V332I, Q382H, V427I, L474P, R463K Q486H, and T487N specific to group II, coinciding with the phylogenetic analysis of the isolates.
Conclusions
Re-emergence of human rabies has mainly occurred in rural areas of Guangxi since 1996. The human rabies incidence rate increased is related with RV positive rate of normal dogs. The Guangxi isolates tested showed a similar pathogenicity and antigenicity. The results of phylogenetic analysis coincide with that of alignment of deduced amino acids. 相似文献
Mixtures of partially O-methylated alditol acetate standards (PMAAs) of Glc, Gal, and Man were synthesized rapidly. Methylation of methyl glycosides was carried out in the presence of BaO/Ba(OH)(2) x 8H(2)O giving rise to mixtures of partially methylated glycosides (PMGs), whose degree of methylation was monitored by TLC. The batch containing the largest mixture of methyl ethers was converted into partially O-methylated alditol acetate derivatives (PMAAs), via successive hydrolysis, reduction, and acetylation, and then subjected to GC and GC-MS analysis. Detailed data on retention times, TIC, and EIMS are now provided. 相似文献