化学感受蛋白(chemosensory proteins，CSPs)在昆虫体内发挥多种功能。为了明确丽蚜小蜂化学感受蛋白EforCSP3是否在其寄主定位和寄主选择性方面发挥嗅觉识别作用，本研究从丽蚜小蜂中鉴定到化学感受蛋白EforCSP3，并对其进行了基因表达、配体结合和分子对接试验。结果表明，EforCSP3在丽蚜小蜂雌蜂头部高表达，成虫期该基因的相对表达量显著高于其他发育时期；荧光竞争结合试验发现EforCSP3与多种寄主植物挥发物之间具有较高的结合力，其中，除月桂烯和α-律草烯外，还有邻苯二甲酸二丁酯、1-辛烯、β-榄香烯和十三烷，均与EforCSP3的结合力最强，这些组分具有被开发为丽蚜小蜂引诱剂的潜力；进一步通过蛋白质结构建模和分子对接预测了可能参与挥发物结合的EforCSP3关键氨基酸残基。结合此前的研究，α-葎草烯和β-月桂烯已被证明可以吸引丽蚜小蜂，本研究亦发现二者与EforCSP3有强的结合力。总之，EforCSP3可能参与丽蚜小蜂的化学信息识别接收过程。

高等植物中，抗坏血酸过氧化物酶（APX）在清除活性氧的过程中发挥重要作用。中华猕猴桃因富含维生素C而成为具有重要经济和营养价值的园艺作物，其APX的相关研究及报道甚少。本研究分离鉴定出中华猕猴桃‘红阳’的两个细胞质APX基因（AcAPX1和AcAPX2）。两个基因的时空表达模式研究发现，两者分别在叶和根中表达量相对较高。氯化钠处理猕猴桃的根可以提高二者的转录水平。利用GFP融合蛋白的亚细胞定位分析显示两个蛋白均定位于细胞质中。两个基因的his标签重组蛋白成功得以原核表达，并测定出酶活。最后，两个基因在拟南芥中过表达可在盐胁迫处理下提高维生素C和谷胱甘肽的含量。我们的研究揭示了中华猕猴桃细胞质APX可保护猕猴桃免受环境不良刺激。

  General combining abilities (GCAs) are very important in utilization of heterosis in maize breeding.  However, its genetic basis is unclear.  In the present study, a set of 118 doubled haploid (DH) lines were induced from F1 generations produced from the cross between the inbred line Zheng 58 and the inbred line W499 belonging to the Reid subgroup.  Using the MaizeSNP50 BeadChip, a high-density genetic map was constructed based on the DH population which included 1?147 bin markers with an average interval length of 2.00 cM.  Meanwhile, the DH population was crossed with three testers including W16-5, HD568, and W556, which belong to the Sipingtou subgroup.  The GCAs of the ear height (EH), the kernel moisture content (KMC), the kernel ratio (KR), and the yield per plant (YPP) were estimated using these hybrids in three environments.  Combining the high-density genetic map and the GCAs, a total of 14 QTLs were detected for the GCAs of the four traits.  Especially, one pleiotropic QTL was identified on chromosome 1 between the SNP SYN16067 and the SNP PZE-101169244 which was simultaneously associated with the GCAs of the EH, the KR, and the YPP.  These QTLs pave the way for further dissecting the genetic architecture underlying GCAs of the traits, and they may be used to enhance GCAs of inbred lines under the fixed heterotic pattern Reid×Sipingtou in China through a marker-assisted selection approach.  

    Soil drying may induce a number of stresses on crops. This paper investigated maize (Zea mays L.) root growth as affected by drought and soil penetration resistance (PR), which was caused by soil drying and tillage in a clayey red soil. Compared with conventional tillage (C) and deep tillage (D), soil compaction (P) and no-till (N) significantly increased soil PR in the 0–15 cm layer. The PR increased dramatically as the soil drying increased, particularly in soil with a high bulk density. Increased soil PR reduced the maize root mass density distribution not only in the vertical profile (0–20 cm) but also in the horizontal layer at the same distance (0–5, 5–10, 10–15 cm) from the maize plant. With an increase in soil PR in pots, the maize root length, root surface area and root volume significantly decreased. Specifically, the maize root length declined exponentially from 309 to 64 cm per plant with an increase in soil PR from 491 to 3 370 kPa; the roots almost stopped elongating when the soil PR was larger than 2 200 kPa. It appeared that fine roots (<2.5 mm in diameter) thickened when the soil PR increased, resulting in a larger average root diameter. The average root diameter increased linearly with soil PR, regardless of soil irrigation or drought. The results suggest that differences in soil PR caused by soil drying is most likely responsible for inconsistent root responses to water stress in different soils.

The bacterial brown spot disease (BBS), caused primarily by Pseudomonas syringae pv. syringae van Hall (Pss), reduces plant vigor, yield and quality in maize. To reveal the nature of the defense mechanisms and identify genes involved in the effective host resistance, the dynamic changes of defense transcriptome triggered by the infection of Pss were investigated and compared between two maize near-isogenic lines (NILs). We found that Pss infection resulted in a sophisticated transcriptional reprogramming of several biological processes and the resistant NIL employed much faster defense responses than the susceptible NIL. Numerous genes encoding essential components of plant basal resistance would be able to be activated in the susceptible NIL, such as PEN1, PEN2, PEN3, and EDR1, however, in a basic manner, such resistance might not be sufficient for suppressing Pss pathogenesis. In addition, the expressions of a large number of PTI-, ETI-, PR-, and WRKY-related genes were pronouncedly activated in the resistant NIL, suggesting that maize employ a multitude of defense pathways to defend Pss infection. Six R-gene homologs were identified to have significantly higher expression levels in the resistant NIL at early time point, indicating that a robust surveillance system (gene-to-gene model) might operate in maize during Pss attacks, and these homolog genes are likely to be potential candidate resistance genes involved in BBS disease resistance. Furthermore, a holistic group of novel pathogen-responsive genes were defined, providing the repertoire of candidate genes for further functional characterization and identification of their regulation patterns during pathogen infection.

WRKY transcription factors are involved in the regulation of response to biotic and abiotic stresses in plants. A fulllength cDNA clone of rice WRKY82 gene (OsWRKY82) was isolated from a cDNA library generated from leaves infected by Magnaporthe grisea. OsWRKY82 contained an entire open reading frame in length of 1 701 bp, and was predicted to encode a polypeptide of 566 amino acid residues consisting of two WRKY domains, each with a zinc finger motif of C2H2,belonging to the WRKY subgroup I. OsWRKY82 shared high identity at the amino acid level with those from Sorghum bicolor, Hordeum vulgare, and Zea mays. The transcript level of OsWRKY82 was relatively higher in stems, leaves, and flowers, and less abundant in grains. It was induced by inoculation with M. grisea and Rhizoctonia solani. However, the inducible expression in incompatible rice-M. grisea interactions was earlier and greater than that in compatible interactions.The expression of OsWRKY82 was up-regulated by methyl jasmonate and ethephon, whereas salicylic acid exerted no effects on its expression. Moreover, OsWRKY82 exhibited transcriptional activation ability in yeast. Additionally,OsWRKY82 transcripts could be induced by wounding and heat shocking, but not by abscisic acid, cold, high salinity and dehydration. By contrast, gibberellin suppressed the expression of OsWRKY82. These indicate that OsWRKY82 is a multiply stress-inducible gene responding to both biotic and abiotic stresses, and may be involved in the regulation of defense response to pathogens and tolerance against abiotic stresses by jasmonic acid/ethylene-dependent signaling pathway.