效应因子表达的精准调控对病原菌从营养阶段到定殖于植物体内的转变至关重要。但是，我们对这些基因的动态调节机制的了解仍有限。本研究通过比较转录组学和染色质免疫沉淀测序方式对稻瘟病菌中甲基化转移酶PoKMT6进行功能分析，发现PoKmt6介导的H3K27me3主要富集在快速进化区，并且这种修饰导致部分分泌蛋白（SP）编码基因和转座子（TE）在菌丝体阶段被沉默。有趣的是，我们发现部分SP基因本身不受H3K27me3修饰，但其附近TE的H3K27me3修饰可以间接沉默这些基因的表达。综上所述，我们的结果表明，在快速进化区，PoKmt6介导的H3K27me3通过抑制附近TE的表达来调节部分SP基因表达。

甘薯(Ipomoea batatas (L.) Lam.)作为一种重要的杂粮作物，在世界各地广泛种植，但深受甘薯病毒病(SPVD)的影响。本研究利用短串联靶标模拟物（STTM）成功抑制甘薯miR397的表达，上调其靶基因漆酶（IbLACs）的表达，使木质素合成途径的上游基因，包括苯丙氨酸解氨酶（PAL）、4-香豆酸辅酶A连接酶（4CL）、羟基肉桂酰CoA:莽草酸/奎宁酸羟基肉桂酰转移酶（HTC）、咖啡酸O-甲基转移酶（COMT）、肉桂醇脱氢酶(CAD)等基因被反馈调控而广泛上调表达。同时，导致PAL和LAC的酶活性显著增加，促进木质素的合成与积累。木质素在细胞壁中的沉积增加了转基因甘薯植株的物理防御能力，有效减少了烟粉虱对SPVD的传播，保证甘薯的健康生长。本研究为甘薯抗病育种和绿色生产提供了新思路。

 

细胞自噬通过维持细胞内物质与能量的动态平衡，进而调控很多发育过程。已知延伸复合物蛋白Elp3具有多种功能并参与调控自噬，但其在稻瘟病菌中的功能仍不清楚。为此，构建了稻瘟病菌Elp3编码基因PoELP3（MGG_05481）的敲除突变体，对其功能进行研究。表型分析结果显示，PoELP3基因的敲除导致稻瘟病菌菌丝生长受抑制，产孢量下降，对细胞壁胁迫剂和盐胁迫剂的敏感性增强，附着胞膨压和致病性显著下降。这些结果表明稻瘟病菌PoElp3在生长发育、胁迫响应和致病过程中均具有重要作用。亚细胞定位结果表明GFP-PoElp3融合蛋白定位于细胞核和细胞质中。为检测稻瘟病菌Elp3在细胞自噬中的作用，将自噬标记GFP-PoAtg8分别导入野生型和突变体中，并通过计算总蛋白中游离GFP占GFP-PoAtg8和游离GFP总量的比例，评估野生型和突变体中自噬的水平。结果表明，无论是在营养充分还是营养不足的条件下，△Poelp3突变体均呈现较高的自噬水平。这可能是导致菌丝生长缓慢的原因。此外，△Poelp3突变体营养菌丝和侵染菌丝的生长均对雷帕霉素更加敏感，但是PoELP3基因的缺失并不影响雷帕霉素对TOR-信号途径下游基因的转录抑制，暗示其并不参与TOR-信号的传导。综上所述，稻瘟病菌Elp3可以通过调控自噬影响无性发育和致病性。但是PoElp3调控自噬的机制仍有待进一步研究。

Soil salinity causes the negative effects on the growth and yield of crops. In this study, two sweet potato (Ipomoea batatas L.) cultivars, Xushu 28 (X-28) and Okinawa 100 (O-100), were examined under 50 and 100 mmol L^–1 NaCl stress. X-28 cultivar is relatively high salt tolerant than O-100 cultivar. Interestingly, real-time quantitative polymerase chain reaction (RT-qPCR) results indicated that sweet potato high-affinity K⁺ transporter 1 (IbHKT1) gene expression was highly induced by 50 and 100 mmol L^–1 NaCl stress in the stems of X-28 cultivar than in those of O-100 cultivar, but only slightly induced by these stresses in the leaves and fibrous roots in both cultivars. To characterize the function of IbHKT1 transporter, we performed ion-flux analysis in tobacco transient system and yeast complementation. Tobacco transient assay showed that IbHKT1 could uptake sodium (Na⁺). Yeast complementation assay showed that IbHKT1 could take up K⁺ in 50 mmol L^–1 K⁺ medium without the presence of NaCl. Moreover, Na⁺ uptake significantly increased in yeast overexpressing IbHKT1. These results showed that IbHKT1 transporter could have K⁺-Na⁺ symport function in yeast. Therefore, the modes of action of IbHKT1 in transgenic yeast could differ from the mode of action of the other HKT1 transporters in class I. Potentially, IbHKT1 could be used to improve the salt tolerance nature in sweet potato.

The information of single nucleotide polymorphisms (SNPs) is quite unknown in sweetpotato.  In this study, two sweetpotato varieties (Xushu 18 and Xu 781) were sequenced by Illumina technology, as well as de novo transcriptome assembly, functional annotation, and in silico discovery of potential SNP molecular markers.  Tetra-primer Amplification Refractory Mutation System PCR (ARMS-PCR) is a simple and sufficient method for detecting different alleles in SNP locus.  Total 153 sets of ARMS-PCR primers were designed to validate the putative SNPs from sequences.  PCR products from 103 sets of primers were different between Xu 781 and Xushu 18 via agarose gel electrophoresis, and the detection rate was 67.32%.  We obtained the expected results from 32 sets of primers between the two genotypes.  Furthermore, we ascertained the optimal annealing temperature of 32 sets of primers.  These SNPs might be used in genotyping, QTL mapping, or marker-assisted trait selection further in sweetpotato.  To our knowledge, this work was the first study to develop SNP markers in sweetpotato by using tetra-primer ARMS-PCR technique.  This method was a simple, rapid, and useful technique to develop SNP markers, and will provide a potential and preliminary application in discriminating cultivars in sweetpotato.

The aldehyde dehydrogenase (ALDH) superfamily of NAD(P)+-dependent enzymes, in general, oxidize a wide range of endogenous and exogenous aliphatic and aromatic aldehydes to their corresponding carboxylic acids and play an essential role in detoxification of reactive oxygen species (ROS) accumulated under the stressed conditions. In order to identify genes required for the stresses responses in the grass crop Oryza sativa, a homologue of ALDH gene (OsALDH22) was isolated and characterized. OsALDH22 is conserved in eukaryotes, shares high homology with the orthologs from aldehyde dehydrogenase subfamily ALDH22. The OsALDH22 encodes a protein of 597 amino acids that in plants exhibit high identity with the orthologs from Zea mays, Sorghum bicolor, Hordeum vulgare and Arabidopsis thaliana, respectively, and the conserved amino acid characteristics for ALDHs are present, including the possible NAD+ binding site (F-V-G-SP- G-V-G), the catalytic site (V-T-L-E-L-G-G-K) and the Cys active site. Semi-quantitative PCR and real-time PCR analysis indicates that OsALDH22 is expressed differentially in different tissues. Various elevated levels of OsALDH22 expression have been detected when the seedlings exposed to abiotic stresses including dehydration, high salinity and abscisic acid (ABA). Transgenic rice plants overexpressing OsALDH22 show elevated stresses tolerance. On the contrary, downregulation of OsALDH22 in the RNA interference (RNAi) repression transgenic lines manifests declined stresses tolerance.