载脂蛋白受体相关蛋白2（Lipophorin receptor-related protein，LRP2）是一类广泛分布于上皮细胞的多功能内吞性受体。哺乳动物中，LRP2通过介导细胞对载脂蛋白的摄取来维持脂质稳态，然而，关于LRP2在昆虫体内脂质稳态中的作用研究尚未见报道。本文系统研究了飞蝗载脂蛋白受体相关基因2 （LmLRP2）的生物学功能。利用RT-qPCR技术分析LmLRP2在虫体不同组织部位和不同发育时期的表达特性，发现其在多种组织中均有较高的表达，包括体壁、翅芽、前肠、后肠、马氏管和脂肪体，蜕皮后表达量先降低，到下次蜕皮前升高。免疫组织化学结果显示，LmLRP2蛋白主要定位于中肠和后肠的细胞膜上。进一步利用RNAi技术沉默LmLRP2的表达后，若虫出现蜕皮困难和蜕皮后短时间内死亡的表型，总致死率达到60%以上。Bodipy染色结果显示，LmLRP2的沉默导致表皮和中肠细胞中性脂含量显著增加，而脂肪体中性脂含量显著减少。进一步利用脂质组学技术分析得到5种甘油二酯（Diglyceride，DG）和3种甘油三酯（Triglyceride，TG），其在中肠累积，而在脂肪体和血淋巴中显著降低。此外，利用甘油三酯测定试剂盒对总TG含量进行测定，发现中肠中总TG含量显著增多，而脂肪体和血淋巴中总TG含量显著减少。本文研究结果表明，主要位于中肠细胞膜上的受体LmLRP2参与中肠脂质到血淋巴和脂肪体的转运，对飞蝗的生长发育至关重要。

Plant-pathogenic Xanthomonas infects a wide variety of host plants and causes many devastating diseases on crops.  Transcription activator-like effectors (TALEs) are delivered by a type III secretion system (T3SS) of Xanthomonas into plant nuclei to directly bind specific DNA sequences (TAL effector-binding elements, EBEs) on either strand of host target genes with an unique modular DNA-binding domain and to bidirectionally drive host gene transcription.  The target genes in plants consist of host susceptibility (S) genes promoting disease (ETS) and resistance (R) genes triggering defense (ETI).  Here we generally summarized the discovery of TALEs in Xanthomonas species, their functions in bacterial pathogenicity in plants and their target genes in different host plants, and then focused on the newly revealed modes of protein action in triggering or suppressing plant defense.

   Paclobutrazol was sprayed at 0, 150, and 300 mg L⁻¹ during the closed canopy stage and the early bud stage with two high-yielding cultivars of rapeseed, Yangguang 2009 and Fengyou 520.  The impact of paclobutrazol on the accumulation and distribution of biomass and its relationship with yield, resistance to lodging and pod shattering were determined.  All the treatments increased the resistance as well as yield.  The maximum yield was obtained when paclobutrazol was applied during the closed canopy stage at 150 mg L^–1.  The plant’s resistance to both lodging and pod shattering was the maximum when paclobutrazol was applied during the early bud stage at 300 mg L^–1.  Paclobutrazol also delayed senescence, with the higher concentration or later spraying leading to more obvious effects; improved the net assimilation rate before the early bud stage; and promoted the relative growth rate of the main growth organ at each stage of growth and maximized the rate and quantities of biomass accumulation.  However, at the higher concentration and later spraying, the increments were smaller.  The spraying also increased the rates of biomass allocation to roots, leaves, and pods, but the rate of allocation to stems decreased as the plants grew shorter.  The higher allocation to roots and the lower allocation to stems favoured resistance to both lodging and pod shattering whereas higher allocation to leaves and pods favoured yield.  The higher concentration or late spraying led to excessive biomass being allocated to roots, which decreased leaf biomass during the bud stage, leading to greater resistance but lower yields. 

    The structural characteristics of protein body accumulation in different endosperm regions of hard wheat cultivar (XM33) and soft wheat cultivar (NM13) under drought stress were investigated. Drought stress treatment was implemented from plant regreening to the caryopsis mature stage. Microscope images of endosperm cells were obtained using resin semi-thin slice technology to observe the distribution and relative area of protein body (PB). Compared with NM13, relative PB area of XM33 was significantly higher in sub-aleurone endosperm region. The amount of accumulation, including the size and relative area of PB, in two wheat cultivars was higher in sub-aleurone region than that in central region at 18 days post anthesis (DPA). Drought stress significantly enhanced the sizes and relative areas of PBs in the dorsal and abdominal endosperms in two wheat cultivars. Particularly for dorsal endosperm, drought stress enhanced the relative PB area at 18 DPA and NM13 (5.0% vs. 6.73%) showed less enhancement than XM33 (5.49% vs. 8.96%). However, NM13 (9.58% vs. 12.02%) showed greater enhancement than XM33 (10.25% vs. 11.7%) at 28 DPA. The protein content in the dorsal and abdominal endosperms of the two wheat cultivars decreased at 12 DPA and then increased until 38 DPA. Drought stress significantly increased the protein contents in the two main regions. From 12 to 38 DPA, the amount of PB accumulation and the protein content were higher in XM33 than those in NM13. The results revealed that PB distribution varied in different endosperm tissues and that the amount of PB accumulation was remarkably augmented by drought stress.

This study investigated the effects of three contrasting soil management regimes and different nutrient treatments on the distribution of water-stable aggregates (>2, 1–2, 0.5–1, 0.25–0.5, and <0.25 mm) and associated soil organic carbon (SOC) and total nitrogen (TN) content in loess soil. A 21-yr long-term experiment was performed, in which soil management regimes include cropland abandonment (Abandonment), bare fallow (Fallow) and wheat-fallow cropping (Cropping). Under Cropping, the following nutrient treatments were employed: control (CK, no nutrient input), nitrogen only (N), nitrogen and potassium (NK), phosphorus and potassium (PK), NP, NPK, and manure (M) plus NPK (MNPK). Results demonstrated that Abandonment significantly increased the content of soil macro-aggregates (>0.25 mm) and mean weight diameter (MWD) at 0–10 and 10–20 cm soil horizons compared with Cropping, whereas Fallow yielded lower values of above two parameters. Abandonment increased SOC and TN contents in all aggregate sizes by 17–62% and 6–60%, respectively, at 0–10 cm soil layer compared with Cropping. Conversely, Fallow decreased SOC and TN contents in all aggregates by 7–27% and 7–25%, respectively. Nevertheless, the three soil management regimes presented similar SOC contents in all aggregates at 10–20 cm soil horizon. Only Cropping showed higher TN content in >0.5 mm aggregates than the two other regimes. Consequently, Abandonment enhanced the partitioning proportions of SOC and TN in >1 mm macro-aggregates, and Fallow promoted these proportions in micro-aggregates compared with Cropping. Under Cropping, long-term fertilization did not affect the distribution of aggregates and MWD values compared with those under CK, except for NPK treatment. Fertilizer treatments enhanced SOC and TN contents in aggregates at all tested soil depths. However, fertilization did not affect the partitioning proportions of SOC and TN contents in all aggregates compared with CK. Comprehensive results showed that different soil management regimes generated varied patterns of SOC and TN sequestration in loess soil. Abandonment enhanced soil aggregation and sequestered high amounts of SOC and TN in macro-aggregates. Long-term amendment of organic manure integrated with NPK maintained soil aggregate stability and improved SOC and TN sequestration in all aggregates in loess soil subjected to dryland farming.

Nitrification inhibitors, such as dicyandiamide (DCD), have been shown to decrease leaching from urea- and ammonium- based fertilizers in agricultural soils. The effect of nitrification inhibitors on nitrifier and denitrifier in short- and long-term intensive vegetable cultivation soils was poorly understood. In this study, the pot trial was conducted to investigate the differential responses of nitrifier (amoA-containing bacteria) and denitrifier (nirK-containing bacteria) to DCD in short-(soil S) and long-term (soil L) intensive vegetable cultivation soils. Quantitative polymerase chain reaction (qPCR) and terminal restriction fragment length polymorphism (T-RFLP) were employed to detect the abundance and composition of amoA- and nirK-containing communities. The results indicated that application of DCD led to a consistently higher NH4 +-N concentration during the whole incubation in soil L, while it was quickly decreased in soil S after 21 days. Furthermore, DCD induced more severe decrease of the abundance of amoA-containing bacteria in soil L than in soil S. However, the abundance of the nirKcontaining community was not significantly affected by DCD in both soils. Long-term vegetable cultivation resulted in a super-dominant amoA-containing bacteria group and less divergence in soil L compared with soil S, and DCD did not cause obvious shifts of the composition of ammonia-oxidising bacteria (AOB). On the contrary, both amoA- and nirK-containing bacterial compositions were influenced by DCD in soil S. The results suggested that long-term intensive vegetable cultivation with heavy nitrogen fertilization resulted in significant shifts of AOB community, and this community was sensitive to DCD, but denitrifiers were not clearly affected by DCD.

Setosphaeria turcica, an essential phytopathogenic fungus, is the primary cause of serious yield losses in corn; however, its pathogenic mechanism is poorly understood. We cloned STK2, a newly discovered mitogen-activated protein kinase gene with a deduced amino acid sequence that is 96% identical to MAK2 from Phaeosphaeria nodorum, 56% identical to KSS1 and 57% identical to FUS3 from Saccharomyces cerevisiae. To deduce Stk2 function in S. turcica and to identify the genetic relationship between STK2 and KSS1/FUS3 from S. cerevisiae, a restructured vector containing the open reading frame of STK2 was transformed into a fus3/kss1 double deletion mutant of S. cerevisiae. The results show that the STK2 complementary strain clearly formed pseudohyphae and ascospores, and the strain grew on the surface of the medium after rinsing with sterile water and the characteristics of the complementary strain was the same as the wild-type strain. Moreover, STK2 complemented the function of KSS1 in filamentation and invasive growth, as well as the mating behavior of FUS3 in S. cerevisiae, however, its exact functions in S. turcica will be studied in the future research.