Molecular Characterization and Expression Patterns of the HkSVP Gene Reveal Distinct Roles in Inflorescence Structure and Floral Organ Development in Hemerocallis fulva

SHORT VEGETATIVE PHASE (SVP) genes are members of the well-known MADS-box gene family that play a key role in regulating vital developmental processes in plants. Hemerocallis are perennial herbs that exhibit continuous flowering development and have been extensively used in landscaping. However, there are few reports on the regulatory mechanism of flowering in Hemerocallis. To better understand the molecular basis of floral formation of Hemerocallis, we identified and characterized the SVP-like gene HkSVP from the Hemerocallis cultivar ‘Kanai Sensei’. Quantitative RT-PCR (qRT-PCR) indicated that HkSVP transcript was mainly expressed in the vegetative growth stage and had the highest expression in leaves, low expression in petals, pedicels and fruits, and no expression in pistils. The HkSVP encoded protein was localized in the nucleus of Arabidopsis protoplasts and the nucleus of onion epidermal cells. Yeast two hybrid assay revealed that HKSVP interacted with Hemerocallis AP1 and TFL1. Moreover, overexpression of HkSVP in Arabidopsis resulted in delayed flowering and abnormal phenotypes, including enriched trichomes, increased basal inflorescence branches and inhibition of inflorescence formation. These observations suggest that the HkSVP gene may play an important role in maintaining vegetative growth by participating in the construction of inflorescence structure and the development of flower organs.

Prosopanche cocuccii (Hydnoraceae): a new species from Southern Brazil

Prosopanche cocuccii is described as a new species from Southern Brazil. It resembles P. bonacinae due to the trigonous rhizome and by the general size of the flower organs. Nevertheless, P. cocuccii is distinguished by the main floral morphological characteristics used to differentiate species. In addition, the new species presents some rare characters for the genus, such as a highly branched rhizome and flowers usually grouped in fascicles. We provide a description, illustrations, field photographs, morphological details under the stereomicroscope, and comments on habitat, ecology, distribution, and conservation of the new species, as well as an updated key for the genus Prosopanche. In addition, we identified that P. cocuccii produces a large number of rhizomes and fruits for each single host specimen of tobacco (Nicotiana tabacum), which resulted in a decrease in height and growth of its only known host plant.

The Putative Role of the NAC Transcription Factor EjNACL47 in Cell Enlargement of Loquat (Eriobotrya japonica Lindl.)

NAC transcription factors (TFs) are plant-specific TFs that play essential roles in plant development; however, the function of NAC TFs in loquat development remains unknown. The natural triploid loquat (Eriobotrya japonica Lindl.), Longquan No.1. B355, has larger organs than its corresponding diploid loquat (B2). Here, we cloned an NAC-like TF (EjNACL47 (NAC-like 47)) from the cDNA of triploid loquat B355 flowers. EjNACL47 has a conserved domain of NAC TFs and is homologous to AtNAC47. Transient expression in tobacco leaves revealed that EjNACL47 localized to the nucleus, and yeast-two-hybrid screening confirmed that the C-terminus displayed transcriptional activity. Interestingly, real-time qRT-PCR indicated that the expression levels of EjNACL47 in leaves and flower organs in triploid loquat (B355) were higher than those in diploid loquat (B2), implying that EjNACL47 might be associated with the larger organ size in B355. Moreover, Arabidopsis lines ectopically expressing EjNACL47 presented obviously larger leaves, flowers, and siliques than the wild-type variant, suggesting that EjNACL47 plays a positive role in Arabidopsis organ enlargement. These results offer insight into the molecular mechanism of NAC TFs involved in regulating organ size in loquat.

Identification and Characterization of MIKCc-Type MADS-Box Genes in the Flower Organs of Adonis amurensis

Adonis amurensis is a perennial herbaceous flower that blooms in early spring in northeast China, where the night temperature can drop to −15 °C. To understand flowering time regulation and floral organogenesis of A. amurensis, the MIKCc-type MADS (Mcm1/Agamous/ Deficiens/Srf)-box genes were identified and characterized from the transcriptomes of the flower organs. In this study, 43 non-redundant MADS-box genes (38 MIKCc, 3 MIKC*, and 2 Mα) were identified. Phylogenetic and conserved motif analysis divided the 38 MIKCc-type genes into three major classes: ABCDE model (including AP1/FUL, AP3/PI, AG, STK, and SEPs/AGL6), suppressor of overexpression of constans1 (SOC1), and short vegetative phase (SVP). qPCR analysis showed that the ABCDE model genes were highly expressed mainly in flowers and differentially expressed in the different tissues of flower organs, suggesting that they may be involved in the flower organ identity of A. amurensis. Subcellular localization revealed that 17 full-length MADSs were mainly localized in the nucleus: in Arabidopsis, the heterologous expression of three full-length SOC1-type genes caused early flowering and altered the expression of endogenous flowering time genes. Our analyses provide an overall insight into MIKCc genes in A. amurensis and their potential roles in floral organogenesis and flowering time regulation.

ZbAGL11, a class D MADS-box transcription factor of Zanthoxylum bungeanum, is involved in sporophytic apomixis

Apomixis is a reproductive model that bypasses sexual reproduction, so it does not require the combination of paternal and maternal gametes but instead results in the production of offspring directly from maternal tissues. This reproductive mode results in the same genetic material in the mother and the offspring and has significant applications in agricultural breeding. Molecular and cytological methods were used to identify the reproductive type of Zanthoxylum bungeanum (ZB). Fluorescence detection of the amplified products of 12 pairs of polymorphic SSR primers showed consistent fluorescence signals for mother and offspring, indicating that no trait separation occurred during reproduction. In addition, the cytological observation results showed differentiation of ZB embryos (2n) from nucellar cells (2n) to form indefinite embryonic primordia and then form adventitious embryos (2n), indicating that the apomictic type of ZB is sporophytic apomixis. The MADS-box transcription factor ZbAGL11 was highly expressed during the critical period of nucellar embryo development in ZB. Unpollinated ZbAGL11-OE Arabidopsis produced fertile offspring and exhibited an apomictic phenotype. The overexpression of ZbAGL11 increased the callus induction rate of ZB tissue. In addition, the results of the yeast two-hybrid experiment showed that ZbAGL11 could interact with the ZbCYP450 and ZbCAD11 proteins. Our results demonstrate that ZbAGL11 can cause developmental disorders of Arabidopsis flower organs and result in apomixis-like phenotypes.

MORPHOLOGY CHARACTERISTICS OF PANICLES AND FLOWER TWELVE GENOTYPES LOCAL RICE OF KUANTAN SINGINGI

Germplasm is a very useful genetic resource for assembling a variety. The preservation of germplasm accompanied by characterization is an effort to provide useful genes. The aims of the research is to identify and characterize 12 genotypes local rice in Kuantan Singingi. This research was used purposive random sampling method. Data were collected by identifying the characteristics of 12 genotypes local rice in Kuantan Singingi directly into the field. Data observations were carried out on samples based on the guidelines for the characterization and evaluation system for rice plants, the National Commission for Germplasm (2003) and Bioversity International, IRRI and WARDA (2007). The characters observed were qualitative and quantitative characters on panicle and flower organs. Observation data were processed using Ms. software. Excel and (NTSYS-pc) version 2.02. The results showed that the diversity of the morphological characters of flowers and panicles, where in the 75% similarity coefficient there are 2 groups, namely group I (PL01 with PL05) and group II (PL03 with PL11).

Silencing of FOREVER YOUNG FLOWER-Like Genes from Phalaenopsis Orchids Promotes Flower Senescence and Abscission

Ectopic expression of FOREVER YOUNG FLOWER (FYF) delays floral senescence and abscission in transgenic Arabidopsis. To analyze the FYF function in Phalaenopsis orchids, two FYF-like genes (PaFYF1/2) were identified. PaFYF1/2 were highly expressed in young Phalaenopsis flowers, and their expression decreased significantly afterward until flower senescence. This pattern was strongly correlated with the process of flower senescence and revealed that PaFYF1/2 function to suppress senescence/abscission during early flower development. Interestingly, in flowers, PaFYF1 was consistently expressed less in petals than in lips/sepals, whereas PaFYF2 was expressed relatively evenly in all flower organs. This difference suggests a regulatory modification of the functions of PaFYF1 and PaFYF2 during Phalaenopsis flower evolution. Delayed flower senescence and abscission, which were unaffected by ethylene treatment, were observed in 35S::PaFYF1/2 and 35S::PaFYF1/2 + SRDX transgenic Arabidopsis plants due to the downregulation of the ethylene signaling and abscission-associated genes EDF1-4, IDA and BOP1/2. These results suggest a possible repressor role for Phalaenopsis PaFYF1/2 in controlling floral senescence/abscission by suppressing ethylene signaling and abscission-associated genes. To further validate the function of PaFYF1/2, PaFYF1/2-VIGS (virus-induced gene silencing) Phalaenopsis were generated and analyzed. Promotion of senescence and abscission was observed in PaFYF1/2-VIGS Phalaenopsis flowers by the upregulation of PeEDF1/2, PeSAG39 and PeBOP1/2 expression, the early occurrence of greening according to their increased chlorophyll content and the reduction in water content in flower organs. Our results support that PaFYF1/2 function as transcriptional repressors to prohibit flower senescence and abscission in Phalaenopsis.

Comparative Transcriptome and WGCNA Reveal Candidate Genes Involved in Petaloid Stamens in Paeonia Lactiflora

Background: The phenomenon of petaloid stamens in Paeonia lactiflora is an important cause of double flower formation. Although research on stamen development in model plants has progressed, the molecular mechanism of P. lactiflora petaloid stamens is still unclear. Results: In this study, a comparative transcriptomic analysis was performed on two cultivars of P. lactiflora (‘Fen Yu Nu’ and ‘Lian Tai’) with different stamen developmental patterns. Using transcriptome sequencing, 89,393 unigenes were identified in P. lactiflora. Trend analysis and weighted gene co-expression network analysis (WGCNA) indicated that 18 candidate genes were likely involved in petaloid stamens, including seven MADS-box genes PlAP3, PlDEFA, PlPI2, PlAG-1, PlSEP3, PlSEP1-1, and PlSEP1-2, and 11 transcription factors (TFs) PlTCP2, PlTCP4, PlTCP9, PlbHLH36, PlICE1, PlLBD38, PlNAC083, PlBLH11, PlPDF2, PlGBF1, and PlIIIA. Based on the selected candidate genes, a hypothetical model of gene expression network regulating petaloid stamens is proposed. Conclusions: Our results provide a collection of candidate genes for the analysis of P. lactiflora petaloid stamens, allowing for in-depth studies of the development pattern of P. lactiflora flower organs, and providing a theoretical basis for related research on petaloid stamens of other herbaceous flowers.