不同虫压下转Bt基因水稻与非转基因水稻生态适合度差异

为了解转基因水稻的基因扩散效率和潜在生态风险,以转Bt抗虫水稻Bt63、R1、R2和非转基因常规水稻Ⅱ优838为试材,采用高、低两个不同虫害胁迫水平和转基因与非转基因水稻相间种植方式,通过观察水稻植株营养生长、结实以及对螟虫危害的抗性表现等差异,研究比较了Bt外源基因插入后对水稻植株适合度的影响.结果表明:在低虫害胁迫条件下,转Bt基因水稻在植株分蘖数、生物量鲜重等营养生长指标方面与非转基因对照品系间无明显差异,但株高、穗长、穗重等指标不及对照,且R2和Bt63与对照间差异显著;在高虫害胁迫条件下,3个转Bt基因水稻品系的分蘖数、穗长、穗重等指标明显高于对照.而不同转基因品系株高适合度效应不同,这可能与受体本身的特性相关.3种转基因水稻的单株结实粒数、千粒重与对照在两种虫害胁迫条件下均无显著性差异,Bt基因对受体植株的结实影响不明显.在高虫害胁迫条件下,3种转Bt基因水稻的抗虫能力均显著优于非转基因水稻,表明Bt基因对受体植株的抗虫性影响显著.同时,本研究结果还表明转Bt基因水稻的适合度代价较小,预示了抗虫转基因水稻外源Bt基因在一定环境条件下具有逃逸的可能,但这种风险比较小.

虫压胁迫对抗虫转基因水稻生长发育及产量性状的影响

在大田条件下,以转基因抗虫水稻Bt63、R1和R2及非转基因水稻汕优63(对照)为材料,设置高、低两种虫压环境条件,研究虫压胁迫对转Bt抗虫基因水稻生长发育及产量相关性状的影响.结果表明:抗虫水稻在虫压胁迫条件下可充分体现出外源基因的抗性特点.在高虫压条件下,3种转Bt基因水稻受螟虫危害程度远低于对照植株,株高、分蘖数、地上部鲜质量、穗长、穗质量、单株穗数、单株实粒数、实粒质量、结实率、千粒重等生长发育和产量指标均高于对照,但仅株高、分蘖数和穗长3个指标与对照有显著差异.因此,抗虫外源Bt基因的引入对水稻结实性不会产生负面效应,高虫压胁迫条件对抗虫转基因水稻产量的影响较小.

Differences in Ecological Fitness Between Bt Transgenic Rice and Conventional Rice Under Insect-infestation Pressures

[Objective] This study aimed to improve density and practicality of the ge- netic map of sunflower （Helianthus annuus L.） by adding some SSR markers. [Method] A total of 123 F8 RILs populations derived from a cross between PAC-2 and RHA-266 were selected as the materials, and a total of 300 pairs of SSR primers were used to screen polymorphic markers between the parents and some of their RILs, and finally 51 pairs of the primers producing polymorphic patterns were selected to construct the genetic map of the RILs populations. [Result] Nineteen pairs of SSR primers did not generate polymorphic patterns or any bands, and 32 SSR pairs showed polymorphism. Thirty-five alleles which distributed in the 15 link- age groups of the maps were detected. The new map covered a total length of 2 914.5 cM, 7.5 cM longer than that of the original map. The average marker interval is 8.1 cM replacing original 9.0 cM. [Conclusion] This study provided reference for genetic map integration and molecular marker assisted selection of sunflower.

Coordinated regulation of active and repressive histone methylations by a dual-specificity histone demethylase ceKDM7A from Caenorhabditis elegans

H3K9me2 and H3K27me2 are important epigenetic marks associated with transcription repression, while H3K4me3 is associated with transcription activation. It has been shown that active and repressive histone methylations distribute in a mutually exclusive manner, but the underlying mechanism was poorly understood. Here we identified ceKDM7A, a PHD （plant homeodomain）- and JmjC domain-containing protein, as a histone demethylase specific for H3K9me2 and H3K27me2. We further demonstrated that the PHD domain of ceKDM7A bound H3K4me3 and H3K4me3 co-localized with ceKDM7A at the genome-wide level. Disruption of the PHD domain binding to H3K4me3 reduced the demethylase activity in vivo, and loss of ceKDM7A reduced the expression of its associated target genes. These results indicate that ceKDM7A is recruited to the promoter to demethylate H3K9me2 and H3K27me2 and activate gene expression through the binding of the PHD domain to H3K4me3. Thus, our study identifies a dual-specificity histone demethylase and provides novel insights into the regulation of histone methylation.

A Design of Acoustic Signal Wireless Acquisition System for Stored Grain Pests Based on Compressed Sensing

In order to achieve the acoustic signal distributed acquisition of stored grain pests, a novel acoustic signal acquisition system was presented based on the wireless sensor networks. And the system architecture, hardware configuration, and software were introduced in detail. Considering bandwidth limitation of wireless sensor networks, random sampling algorithm based on the compressed sensing theory was proposed. The developed acoustic signal acquisition system was applied in sampling the crawl acoustic signal of Tribolinm castaneum Herbst adults in granary. Preliminary experimentation indicated the rationality and practicability of the developed system and the proposed algorithm. They can implement the remote, real-time, and reliable wireless transmission for the acoustic signal sampled data of multiple points stored grain pests effectively.

RAB-27 and its effector RBF-1 regulate the tethering and docking steps of DCV exocytosis in C.elegans

The molecular mechanisms by which dense core vesicles(DCVs) translocate,tether,dock and prime are poorly understood.In this study,Caenorhabditis elegans was used as a model organism to study the function of Rab proteins and their effectors in DCV exocytosis.RAB-27/AEX-6,but not RAB-3,was found to be required for peptide release from neurons.By analyzing the movement of DCVs approaching the plasma membrane using total internal reflection fluorescence microscopy,we demonstrated that RAB-27/AEX-6 is involved in the tethering of DCVs and that its effector rabphilin/RBF-1 is required for the initial tethering and subsequent stabilization by docking.