小麦抗旱相关基因TaPYL4的功能分析及标记开发

本研究从历史数据以及公开文章中收集了57个与大豆种子可溶性糖含量相关的数量性状位点(QTLs)。通过meta、overview和共线性分析来细化QTL区间，共得到8个共有QTL。使用染色体片段代换系(CSSLs)群体对这些共有QTL进行验证，选择了两个包含共有QTL和有导入片段的品系：其中一个与共有QTL区间相关的一个品系可溶性糖含量较高，另一个品系可溶性糖含量较低。在种子发育的早期、中期和晚期对这两个品系进行转录组测序，分别鉴定出158个、109个和329个差异表达基因。通过重测序数据和共有QTL区间分析，在野生大豆遗传导入片段中鉴定出3个候选基因Glyma.19G146800、Glyma.19G122500和Glyma.19G128500。通过对两个CSSL亲本SN14和ZYD00006的序列比对，发现Glyma.19G122500编码序列发生单核苷酸多态性(SNP)突变，导致氨基酸序列发生非同义突变，影响了蛋白质结构。基于这一SNP，我们开发了竞争性等位基因特异性PCR (KASP)标记，并将其用于CSSL品系的鉴定。这些结果为进一步鉴定大豆可溶性糖相关基因及进一步育种奠定了基础。

本文探讨了PEG诱导的渗透胁迫与荫蔽效应之间的关系。荫蔽和非荫蔽条件下，大豆品种C-103受到聚乙二醇（PEG-6000）诱导的渗透胁迫。在两种光环境中，PEG诱导的渗透胁迫都显著降低了相对含水量、形态参数、碳水化合物和叶绿素含量，大豆幼苗的渗透调节物质、活性氧和抗氧化酶明显增加。本研究表明，在非荫蔽条件下生长的大豆幼苗，PEG诱导的渗透胁迫比荫蔽下的幼苗产生更多的丙二醛和过氧化氢。同样，在干旱胁迫下，被遮荫的植株比不被荫蔽的植株积累了更多的糖和脯氨酸。因此，本研究结果揭示了未遮荫的植物比遮荫的植物对 PEG诱导的渗透胁迫更敏感，这提示荫蔽可以增强植物对渗透胁迫的保护机制，或者至少不会增强 PEG诱导的渗透胁迫对大豆幼苗的不利影响。

Either arbuscular mycorrhizal fungi (AMF) or polyamines (PAs) may change root system architecture (RSA) of plants, whereas the interaction of AMF and PAs on RSA remains unclear. In the present study, we studied the interaction between AMF (Paraglomus occultum) and exogenous PAs, including putrescine (Put), spermidine (Spd) and spermine (Spm) on mycorrhizal development of different parts of root system, plant growth, RSA and carbohydrate concentrations of 6-m-old citrus (Citrus tangerine Hort. ex Tanaka) seedlings. After 14 wk of PAs application, PA-treated mycorrhizal seedlings exhibited better mycorrhizal colonization and numbers of vesicles, arbuscules, and entry points, and the best mycorrhizal status of taproot, first-, second-, and third-order lateral roots was respectively found in mycorrhizal seedlings supplied with Put, Spd and Spm, suggesting that PAs might act as a regulated factor of mycorrhizal development through transformation of root sucrose more into glucose for sustaining mycorrhizal development. AMF usually notably increases RSA traits (taproot length, total length, average diameter, projected area, surface area, volume, and number of first-, second-, and third-order lateral roots) of only PA-treated seedlings. Among the three PA species, greater positive effects on RSA change and plant biomass increment of the seedlings generally rank as Spd>Spm>Put, irrespective of whether or not AMF colonization. PAs significantly changed the RSA traits in mycorrhizal but not in non-mycorrhizal seedlings. It suggests that the application of PAs (especially Spd) to AMF plants would optimize RSA of citrus seedlings, thus increasing plant growth (shoot and root dry weight).

Phytophthora root rot is one of the most prevalent diseases in the world, which can infect the seedlings and plants, withsubstantial negative impact on soybean yield and quality. MicroRNAs (miRNAs) are a class of post-transcriptionalregulators of gene expression during growth and development of organisms. A soybean disease-resistance varietySuinong 10 was inoculated with Phytophthora sojae race No. 1, and the specific miRNA resistant expression profile wasacquired by microarray for the first time. Different expressional miRNAs have been found after comparing the results ofthe treated sample with the control sample. Furthermore, the target genes of different expressional miRNAs were predicted.Two miRNAs, cbr-mir-241 and ath-miR854a, regulated the disease-resistance process directly through their targets, someenzymes. Another two miRNAs, gma-miR169a and ath-miR169h, participated in disease-resistance regulation as transcriptionfactors. Similarly, one miRNA, ptc-miR164f, has been reported to regulate the plant development. All of these studieswould be served as the foundation for exploring the resistance mechanism.

Soybean is a major cash crop in the world, and its oil content was one of the very important traits. Therefore, the study of gene mapping for oil content in soybean is very important for breeding application. At present, at least 130 QTL loci for soybean oil content have been published; however, the mapping results of oil content were dispersed and a coalescent public map should be established to integrate the published QTLs, and to more efficiently mine genes based on the metaanalysis method of the bioinformatics tools. This study was to construct an integrated map of QTLs for soybean oil content and accelerate the application of bioinformation resource related to oil content improvement in the practice of soybean breeding. We collected information of 130 QTLs reported over the past 20 yr for soybean oil content and used the Software BioMercator 2.1 to project QTLs from their own maps onto a reference map, which was an early-integrated map constructed by Song (2004) for oil-content quantitative trait loci (QTLs) in soybean. Gene mining was performed based on the meta-analysis by running the local ver. GENSCAN and InterProScan. The confidence interval of QTLs was efficaciously narrowed using the meta-analysis method, and 25 consensus QTLs were mapped on the reference map. Using a local version of GENSCAN, 12 805 sequences in the consensus QTL intervals were predicted. With BLAST, these predicted sequences were aligned to gene sequences from the International Protein Index database using InterProScan locally. Thirteen predicted genes were in the class of the geme ontology (GO) accession (0006631), which were involved in the fatty acid metabolic process. These genes were analyzed using BLAST at the NCBI website to examine whether they were related to oil content. Six genes were found in the oil-synthesis pathway. Twenty-five consensus QTLs and six genes were found in the oil-synthesis pathway. These results would lay the foundation for marker-assisted selection and mapping QTL precisely, and these genes will facilitate the researches on the gene mining of oil synthesis and molecular breeding in soybean.