A majority of land plants can form symbiosis with arbuscular mycorrhizal (AM) fungi. MicroRNAs (miRNAs) have been implicated to regulate this process in legumes, but their involvement in non-legume species is largely unknown. In this study, by performing deep sequencing of sRNA libraries in tomato roots and comparing with tomato genome, a total of 700 potential miRNAs were predicted, among them, 187 are known plant miRNAs that have been previously deposited in miRBase. Unlike the profiles in other plants such as rice and Arabidopsis, a large proportion of predicted tomato miRNAs was 24 nt in length. A similar pattern was observed in the potato genome but not in tobacco, indicating a Solanum genus-specific expansion of 24-nt miRNAs. About 40% identified tomato miRNAs showed significantly altered expressions upon Rhizophagus irregularis inoculation, suggesting the potential roles of these novel miRNAs in AM symbiosis. The differential expression of five known and six novel miRNAs were further validated using qPCR analysis. Interestingly, three up-regulated known tomato miRNAs belong to a known miR171 family, a member of which has been reported in Medicago truncatula to regulate AM symbiosis. Thus, the miR171 family likely regulates AM symbiosis conservatively across different plant lineages. More than 1000 genes targeted by potential AM-responsive miRNAs were provided and their roles in AM symbiosis are worth further exploring.

on-current I c2on is larger than the off-state current I c2off , and a large on-current through the passives causes larger loss. MEASUREMENT RESULTSThe VCOs were designed and fabricated in the TSMC 0.18 lm 1P6M CMOS technology. Figure 3 shows the micrograph of the proposed VCO with a chip area of 0.991 3 0.815 mm 2 including all test pads and dummy metal. Four inductors L are shown. With the supply voltage of V dd 5 0.8 V, the low-/high-band current and power consumption of the core VCO are 6.55/6.85 mA and 5.24/5.48 mW, respectively. Figure 4 shows the tuning ranges of the oscillation frequency while varying V tune . While the control voltage V tune was tuned from 0 to 2.0 V, the VCO operates between 4.5/7.18 and 4.64/7.55 GHz. Figure 4(a) shows the output spectrum at 4.63 GHz, with 211.88 dBm output power. Figure 5(b) shows the output spectrum at 7.46 GHz, with 22.04 dBm output power. The measured high-band/lowband phase noise shown in Figure 6 is 2124.25/2115.84 dBc/ Hz at 1 MHz offset frequency from the center frequency. The measured phase noise shows the 1/Dx 2 -dependence at the offset frequency greater than 1 MHz. and the 1/Dx 3 -dependence at the offset frequency between 100 KHz and 1 MHz. The high-/lowband figure of merit (FOM) is 2194.25/2182.29 dBc/Hz. The FOM is calculated using the equation defined bywhere L{Dx} is the single side-band phase noise measured at Dx offset from x o carrier frequency and P DC is DC power consumption in mW. Table 1 is the performance comparison. CONCLUSIONA novel dual-band standing wave VCO with LH LC network has been proposed and successfully implemented. The dual-band function is based on fundamental and harmonic mode switching using MOSFET as the switching device. The dual-band operation has been obtained by exciting harmonic-mode operation using the MOSFET switch without the need to reconfigure the LH LC network. The VCO generates differential signals in the high-band frequency range of 7.18-7.55 GHz and in the lowband frequency range of 4.5-4.64 GHz. The measured data show the proposed fundamental and high-order harmonic mode switching technique can be used to design a dual-band VCO with good FOM. ACKNOWLEDGMENTThe experimental support of CIC is acknowledged. REFERENCES 1.

Arbuscular mycorrhiza (AM) is a mutualistic symbiosis formed between most land plants and Glomeromycotina fungi. During the symbiosis, plants provide organic carbon to fungi in exchange for mineral nutrients. Previous legume studies showed that the Required for Arbuscular Mycorrhization2 (RAM2) gene is necessary for transferring lipids from plants to AM fungi (AMF) and is also likely to play a ‘signaling’ role at the root surface. To further explore RAM2 functions in other plant lineages, in this study, two rice (Oryza sativa) genes, OsRAM2 and OsRAM2L, were identified as orthologs of legume RAM2. Examining their expression patterns during symbiosis revealed that only OsRAM2 was strongly upregulated upon AMF inoculation. CRISPR/Cas9 mutagenesis was then performed to obtain three Osram2 mutant lines (-1, -2, and -3). After inoculation by AMF Rhizophagus irregularis or Funneliformis mosseae, all the mutant lines showed extremely low colonization rates and the rarely observed arbuscules were all defective, thus supporting a conserved ‘nutritional’ role of RAM2 between monocot and dicot lineages. As for the ‘signaling’ role, although the hyphopodia numbers formed by both AMF on Osram2 mutants were indeed reduced, their morphology showed no abnormality, with fungal hyphae invading roots successfully. Promoter activities further indicated OsRAM2 was not expressed in epidermal cells below hyphopodia or outer cortical cells enclosing fungal hyphae, but expressed exclusively in cortical cells containing arbuscules. It therefore suggested an indirect role of RAM2 rather than a direct involvement in determining the symbiosis signals at the root surface.

The Rsv1 - h gene in cultivar Suweon 97, which confers resistance to SMVs, was mapped to a 97.5-kb location (29,815,195-29,912,667 bp on chromosome 13) in the Rsv1 locus, thereby providing additional insights into the molecular nature underlying variations in resistance alleles in this particular locus. Soybean mosaic virus (SMV) is a well-known devastating pathogen of soybean (Glycine max (L.) Merrill.) causing significant yield losses and seed quality deterioration. A single dominant allele, Rsv1-h, which confers resistance to multiple SMV strains, was previously reported in the cultivar Suweon 97, but its exact location is unknown. In the present study, Suweon 97 was crossed with a SMV-sensitive cultivar, Williams 82. Inoculating 267 F individuals with two Chinese SMV strains (SC6-N and SC7-N) demonstrated that one single dominant gene confers SMV resistance. Another 1,150 F individuals were then screened for two simple sequence repeat (SSR) markers (BARCSOYSSR_13_1103 and BARCSOYSSR_13_1187) that flank the Rsv1 locus. Seventy-four recombinants were identified and 20 additional polymorphic SSR markers within the Rsv1 region were then employed in genotyping these recombinants. F and F recombinant lines were also inoculated with SC6-N and SC7-N to determine their phenotypes. The final data revealed that in Suweon 97, the Rsv1-h gene that confers resistance to SC6-N and SC7-N was flanked by BARCSOYSSR_13_1114 and BARCSOYSSR_13_1115, two markers that delimit a 97.5-kb region in the reference Williams 82 genome. In such region, eight genes were present, of which two, Glyma13g184800 and Glyma13g184900, encode the characteristic CC-NBS-LRR type of resistance gene and were considered potential candidates for Rsv1-h.

Summary Arbuscular mycorrhizal (AM) symbiosis relies on the formation of arbuscules for efficient nutrient exchange between plants and AM fungi. In this study, we identified a novel kinase gene in rice named OsADK1 (Arbuscule Development Kinase 1) that is required for arbuscule development. By obtaining OsADK1pro::GUS transgenic rice plants and also generating Osadk1 mutants via CRISPR/Cas9 technique, OsADK1 was revealed to be specifically induced in the arbusculated cortical cells and mutations in OsADK1 resulted in an extremely low colonisation rate (c. 3%) of rice roots by AM fungus Rhizophagus irregularis. In the mutant roots, the very few observed arbuscules nearly all arrested at an early ‘trunk‐forming’ phase without forming any branches. Increasing the inoculum strength of AM fungus or cocultivation with a wild‐type nurse plant did not result in the rescue of the arbuscule phenotype. Transcriptome sequencing of both nursed and un‐nursed Osadk1 mutants then revealed that the mutation of OsADK1 could greatly affect the AM symbiotic programme, including many key transcription factors such as RAM1 and WRI5. OsADK1 therefore represents a new rice kinase that is required for arbuscule branching. Its identification opens a new window to explore the elaborate signal transduction pathway that determines arbuscule development during plant–fungus symbiosis.