MiRNA-mediated Changes in DNA Methylation Affect the Expression of Genes Involved in the Thickness of Pod Canopy Trait in Brassica Napus

Background: Methylation plays an important role in regulating crop development, but little is known about how methylation regulates plant architecture in rapeseed (Brassica napus). Here, we examined how methylation affects the TPC (thickness of pod canopy) trait in rapeseed by performing genome-wide methylation analysis of two extreme TPC lines. Results: We detected significant differences in overall methylation levels between the high- and low-TPC lines in the CG, CHG, and CHH contexts in the promoters of genes in the stem apex and flower bud. In flower buds, 26 genes had significantly higher methylation levels in the high-TPC samples compared to the low-TPC samples, resulting in significantly reduced gene expression. By contrast, in the stem apex samples, the promoter regions of 22 genes were hypermethylated in the high- vs. low-TPC samples. The promoters of 19 and 21 genes had significantly reduced methylation levels in the flower bud and stem apex, respectively, of the high- vs. low-TPC samples, resulting in significantly higher expression levels. Some of these differentially expressed genes are associated with TPC-related traits, such as BnaC03g53050D (UBC32), BnaA05g26660D (CYSB), BnaA10g07880D (TCP 1), BnaAnng09670D (SMP1), BnaA09g02000D (SDH2-2), BnaC01g12960D (NRT1.8), and BnaC09g30490D (TAF15b). In addition, 14 important genes related to growth and development were differentially regulated between the two groups due to miRNA-mediated differences in methylation levels in their promoters. For example, hypermethylation in the promoter region of BnaCnng64040D (Lipase family protein) mediated by miR159a led to significantly reduced gene expression in flower buds of high-TPC vs. low-TPC lines. Conclusions: These results, together with our previously generated RNA-seq and miRNA profiling data, indicate that both methylation and miRNAs are involved in regulating the expression of genes in nitrogen-related metabolic pathways, thereby affecting the TPC trait in B. napus, providing a reference for uncovering the molecular mechanism regulating this crucial trait.

Comparative Transcriptome Analysis of a Fan-shaped Inflorescence in Pineapple Using RNA-seq

Background: Pineapple plant usually has a capitulum. However, a fan-shaped inflorescence was evolved in an exceptional material, having multiple crown buds. In order to reveal the molecular mechanisms of the formation of the fan-shaped inflorescence, fruit traits and the transcriptional differences between a fan-shaped inflorescence (FI) and a capitulum inflorescence (CI) pineapples were analyzed in the three tissues, i.e., the flower stem apex (FIs and CIs), the base of the inflorescence (FIb and CIb), and the inflorescence axis (FIa and CIa).Results: Except for a clear differentiation of inflorescence morphology, no significant differences in the structure of inflorescence organs and the main nutritional components (soluble solids, soluble sugar, titratable acid, and VC) in fruits were found between the two pineapples. Between the fan- and capitulum-shaped inflorescences, a total of 5370 differentially expressed genes (DEGs) were identified across the three tissues; and 3142, 2526 and 2255 DEGs were found in the flower stem apex, the base of the inflorescence, and the inflorescence axis, respectively. Of these genes, there were 489 overlapping DEGs in all three tissue comparisons. In addition, 5769 DEGs were identified between different tissues within each pineapple. Functional analysis indicated between the two pineapples that 444 transcription factors (TFs) and 206 inflorescence development related genes (IDGs) were differentially expressed in at least one tissue comparison, while 45 TFs and 21 IDGs were overlapped across the 3 tissues. Among the 489 overlapping DEGs in the 3 tissue comparisons between the two pineapples, excluding the IDGs and TFs, 80 of them revealed a higher percentage of involvement in the biological processes relating to response to auxin, and reproductive processes. RNA-seq value and real-time quantitative PCR analysis exhibited the same gene expression patterns in the three tissues. Conclusions: Our result provided novel cues for understanding the molecular mechanisms of the formation of fan-shaped inflorescence in pineapple, making a valuable resource for the study of plant breeding and the speciation of the pineapples.

Adventitious shoot regeneration from leaf and stem explants of Salix matsudana Koidz

Currently, the leaf and stem as explants for rapid propagation in vitro remained unknown in Salix matsudana. Multiple shoots were regenerated from leaf and stem (stem apex and stem with axil). The optimum medium for callus regeneration and shoots induction from leaf was on WPM medium containing 6.0 mg/l zeatin (Z) and 0.75 mg/l NAA. The optimum medium of shoot induction from stem apex was on MS medium supplemented with 8.0 mg/l Z and 1.0 mg/l NAA, and from stem with axil was on MS with 8.0 mg/l Z and 0.5 mg/l NAA. Rooting of regenerated shoots was obtained on the same medium supplemented with 1.0 mg/l activated charcoal.

Gleadovia konyakianorum (Orobanchaceae), a new species from Nagaland, India

A new species of the genus Gleadovia from Nagaland, Northeastern India, Gleadovia konyakianorum is here described and illustrated. The new species differs from its presently known congeners, such as G. banerjiana, G. mupinense and G. ruborum in having strictly 1-flowered inflorescence borne at stem apex, urceolate calyx unequally 5-lobed at apical part, white corolla, narrowly ovoid to fusiform, ca. 1 cm long anther, moderately shorter style, 0.5–0.6 cm long and in narrowly subulate, comparatively longer stigma, to 2.5 cm long. Identification key to the species of Gleadovia is given.

Lectotypification of the name Gleadovia ruborum Gamble & Prain (Orobanchaceae)

The genus Gleadovia was described by J.S Gamble and D. Prain (1900: 488) including a single species, G. ruborum Gamble & Prain (1900: 489) on the base of plants collected in 1898 from Bodyar, Jauansar in N.W. Himalaya. The genus is represented now by 3 species distributed in India and China. These species are: G. ruborum Gamble & Prain (India and China), G. mupinense Hu (1939: 2) (China) and G. banerjiana Deb (1956: 799) (India). G. ruborum is characterized by ovate or oblong leaves, 3- to several pedicelate flowers clustered at stem apex, obovate bract, spatulate-oblanceolate bracteoles, a tubular-campanulate calyx funnelform upward, much shorter than corolla, to 1.8 cm in diam., comparatively shorter pedicel, to 2.5 cm long and by corolla glabrous abaxially, villous adaxially (J.S. Gamble 26949-K! (K000999865, K000999866); CAL! (Acc. No. 329959)), whereas G. mupinense is characterized by oblong-lanceolate or lanceolate leaves, 3- to several pedicelate flowers borne on upper part of stem, oblong-lanceolate bract, linear-lanceolate bracteoles, a tubular calyx slightly enlarged upward, much shorter than corolla, to 1.2 cm in diam., longer pedicel, to 9 cm long and by densely villous corolla lobes on both sides (T.T. Yu 2189-PE! (PE - 1643589-00032337)), while G. banerjiana is characterized by lanceolate or ovate-lanceolate, spatulate leaves, 1–3 subsessile, ebracteate, ebraceolate flower(s) borne at the stem apex, a spathaceous calyx more or less equal to corolla, to 4.5 cm in diam. and densely hairy corolla lobes inside (D.B. Deb 2247A-CAL! (Acc. No. 329964)). When Gamble and Prain (1900) described G. ruborum, they mentioned in the protolouge the collections of J.S. Gamble, F. Gleadow, J.F. Duthie and Duthie’s collectors collected in 1898 from Bodyar, Jaunsar in N.W. Himalaya. Thus the cited authentic collections consist of several elements collected by different collectors. Therefore it warrants the typification under Art. 9.5 of the International Code of Nomenclature (McNeill et al. 2012). Hence a lectotype is designated here from the original collections.

New species of Anthurium (Araceae) from Chucantí Nature Reserve, eastern Panama

In the present paper we describe two new endemic species of Anthurium, discovered during field trips to study the Araceae flora of the Chucantí Nature Reserve (Reserva Natural Chucantí) located in the province of Darién, Panama. Anthurium annularum sp. nov., a member of section Xialophyllium, is principally characterized by its hemiepiphytic climbing habit, stems with ring-shaped nodes with short internodes alternating with much longer internodes, a yellow-green spadix and pale green globose berries which are nearly translucent toward the base. A. chucantiense sp. nov., a member of section Polyneurium, is characterized by its epiphytic habit, short internodes at stem apex, terete petioles, blades with obscure primary lateral veins, greenish to pale orange spadix and narrowly ovoid, and bluntly pointed red-orange berries.

Durabilidade pós-produção de vasos de três espécies de Kalanchoe (Crassulaceae) em diferentes substratos

Potted plants have wide appeal among ornamental plants and one of the most produced for the market belong to the genus Kalanchoe. One aspect to be observed in potted plants is their durability post-production when maintained in indoors conditions as offices and homes. This study aimed to evaluate the durability of the pot post-production life of three species of Kalanchoe (K. marmorata, K. thyrsiflora and K. tubiflora) on different substrates. The experiment was arranged in a completely randomized design with 40 replicates per treatment in factorial 3 x 2 (three species of Kalanchoe x two substrates - washed sand and coconut fiber). After 30 days, it was evaluated the general aspects as changes in color, leaf abscission and shading of the stem apex. It was found significant differences between species and also between the substrates tested, but only in relation to the general aspects. The species Kalanchoe marmorata and K. tubiflora stood out by receiving top grades in most of the evaluated characteristics. The best substrate that provided plants the maintenance of the most of their ornamental characteristics over the 30 days was the coconut fiber.