Evolution and expression of LEAFY genes in ferns and lycophytes

Background The LEAFY (LFY) transcription factors are present in algae and across land plants. The available expression and functional data of these genes in embryophytes suggest that LFY genes control a plethora of processes including the first zygotic cell division in bryophytes, shoot cell divisions of the gametophyte and sporophyte in ferns, cone differentiation in gymnosperms and floral meristem identity in flowering plants. However, their putative plesiomorphic role in plant reproductive transition in vascular plants remains untested. Results We perform Maximum Likelihood (ML) phylogenetic analyses for the LFY gene lineage in embryophytes with expanded sampling in lycophytes and ferns. We recover the previously identified seed plant duplication that results in LEAFY and NEEDLY paralogs. In addition, we recover multiple species-specific duplications in ferns and lycophytes and large-scale duplications possibly correlated with the occurrence of whole genome duplication (WGD) events in Equisetales and Salviniales. To test putative roles in diverse ferns and lycophytes we perform LFY expression analyses in Adiantum raddianum, Equisetum giganteum and Selaginella moellendorffii. Our results show that LFY genes are active in vegetative and reproductive tissues, with higher expression in early fertile developmental stages and during sporangia differentiation. Conclusions Our data point to previously unrecognized roles of LFY genes in sporangia differentiation in lycophytes and ferns and suggests that functions linked to reproductive structure development are not exclusive to seed plant LFY homologs.

​The Effects of Mesorhizobium ciceri Inoculation and Different Doses of Vermicompost Treatments on the Yield Components and Yield of Chickpea (Cicer arietinum L.) under Semi-arid Mediterranean Highland Condition of Turkey

Background: This study was conducted in 2016-2017 to determine the effects of Mesorhizobium ciceri inoculation and different doses of vermicompost applications on the yield components and yield of chickpea under semi-arid Mediterranean highland condition of Turkey. Methods: Mesorhizobium ciceri inoculant were applied to seeds (at 108 cfu bacteria per seed dose) as microbial fertilizer in the experiments. Vermicompost doses were 0, 1000, 2000 and 3000 kg ha-1. The trials were set up with three replications according to the randomized complete blocks design. Conclusion: Plant height, first pod height, pod number per plant, number of seeds per plant, 100 grain weight and grain yield were determined as 56.1-61.9 cm, 29.4-34.9 cm, 31.4-46.3 pods plant-1, 32.9-44.0 seed plant-1, 30.4-37.4 g and 1463-2072 kg ha-1, respectively. Co-application of 1000 kg ha-1 vermicompost with Mesorhizobium ciceri inoculation produced the highest values for all examined parameters for both years. Further applications of vermicompost reduced yield and related components. Control parcels and excess vermicompost applications (2000 and 3000 kg ha-1) produced lowest values. Mesorhizobium ciceri inoculation produced medium values between Co-application of 1000 kg ha-1 vermicompost with Mesorhizobium ciceri and control and excess vermicompost applied conditions. In conclusion, use of Mesorhizobium ciceri + 1000 kg ha-1 vermicompost was recommended in chickpea cultivation for maximum yield in the ecological conditions of Siirt province of Turkey or in similar ecologies.

An Improved Assembly Strategy Helps Parsing the Cryptic Mitochondrial Genome Evolution in Plants

Although plant mitochondrial genomes (mitogenomes) are small, they exhibit considerable complexity not seen in other eukaryotic mitogenomes. Assembly and analysis of plant mitogenomes is hampered by their large variations in structure and size, and the mitogenome remains the last genome to be deciphered in many plant species. As a result, very few plant mitogenomes have been assembled and little is known regarding their evolution. In this study, a strategy was devised for assembly of mitogenomes from existing short reads from whole-genome sequencing projects. The strategy combined current tools and manual steps to resolve the two main challenges to mitogenome assembly: repeat and plastid insertion sequences. High-quality complete mitogenomes were assembled for 23 species from five families of the Fagales. Mitogenomes varied 2.4 times in size. The largest, Carpinus cordata, did not contain large amounts of unique sequences, but instead contained a high proportion of sequences homologous to other Fagales. Further analysis of the Fagales mitogenomes revealed highly mosaic characteristics, with horizonal transfer (HGT)-like sequences identified from almost all seed plant taxa. Independent and unequal transfers of third-party DNA may partially account for the HGT-like fragments and unbalanced size expansions observed in Fagales mitogenomes. Supporting this, a mitochondrial plasmid of nuclear origin was found in Carpinus, and this may represent an intermediate stage prior to incorporation into the mitogenome. The approaches used in this study are widely applicable and provide new insights into the mechanisms of mitogenome evolution in plants.

The other sexual revolution: hormonal control of family planning in plants

The development of hormonal contraceptives stands out as a key contribution of biochemistry to the 20th century, part of the wider ‘sexual revolution’ that dramatically changed society in many Western countries. But unbeknown to them, the pioneers of the contraceptive pill had been beaten to the idea by a few hundred million years, by a rather unlikely group of organisms that have been using hormones as contraceptives since their own sexual revolutions back in the swinging Palaeozoic. Since their successful conquest of land in the Ordovician, land plants had been restricted in the genetic mixing and expansion of populations by their relative immobility. A series of key innovations in the seed plant group, and in particular in flowering plants, enabled plants to mate and to disperse their offspring over much longer distances, by harnessing the wind or animals to provide mobility. However, all this ‘outsourcing’ created new challenges; coordinating and optimizing reproductive effort is not straightforward when it depends on a third party. Here, I discuss some of the key signalling molecules – sex hormones, as it were – that plants use to plan their families and manage their fertility, and why this matters to us, now more than ever.

Ancient noeggerathialean reveals the seed plant sister group diversified alongside the primary seed plant radiation

Noeggerathiales are enigmatic plants that existed during Carboniferous and Permian times, ∼323 to 252 Mya. Although their morphology, diversity, and distribution are well known, their systematic affinity remained enigmatic because their anatomy was unknown. Here, we report from a 298-My-old volcanic ash deposit, an in situ, complete, anatomically preserved noeggerathialean. The plant resolves the group’s affinity and places it in a key evolutionary position within the seed plant sister group. Paratingia wuhaia sp. nov. is a small tree producing gymnospermous wood with a crown of pinnate, compound megaphyllous leaves and fertile shoots each with Ω-shaped vascular bundles. The heterosporous (containing both microspores and megaspores), bisporangiate fertile shoots appear cylindrical and cone-like, but their bilateral vasculature demonstrates that they are complex, three-dimensional sporophylls, representing leaf homologs that are unique to Noeggerathiales. The combination of heterospory and gymnospermous wood confirms that Paratingia, and thus the Noeggerathiales, are progymnosperms. Progymnosperms constitute the seed plant stem group, and Paratingia extends their range 60 My, to the end of the Permian. Cladistic analysis resolves the position of the Noeggerathiales as the most derived members of a heterosporous progymnosperm clade that are the seed plant sister group, altering our understanding of the relationships within the seed plant stem lineage and the transition from pteridophytic spore-based reproduction to the seed. Permian Noeggerathiales show that the heterosporous progymnosperm sister group to seed plants diversified alongside the primary radiation of seed plants for ∼110 My, independently evolving sophisticated cone-like fertile organs from modified leaves.

Intermediate Epicotyl Physiological Dormancy in the Recalcitrant Seed of Quercus chungii F.P.Metcalf with the Elongated Cotyledonary Petiole

Control of seed germination and dormancy is important in seed plant adaptation and evolution. When studying seed dormancy of Quercus species, we observed a substantially delayed shoot emergence following a fast root emergence in Quercus chungii F.P.Metcalf. Since epicotyl physiological dormancy (PD) has not been reported in Quercus section Cyclobalanopsis, we examined seed morphology and germination in Q. chungii and aimed to document epicotyl PD in the seeds. The embryo was fully developed in fresh ripe seeds. The elongating cotyledonary petiole pushed the embryo axis out of the seed during germination, which differed from observations in other Quercus species. Shoots emerged from seeds with developing roots after 3 months of warm stratification (35/25 °C), reaching the highest percentage of shoot emergence in seeds after 5 months. Seeds were recalcitrant and displayed a yet unreported epicotyl PD type, for which we propose the formula Cnd(root) ‒ Cp’’ 2b(shoot). Early emergence and development of the root system in Q. chungii seeds with epicotyl PD appears to be a mechanism to maintain a constant water supply to the shoot during plumule development and emergence. Our documentation of seed germination will provide guidance for the conservation and restoration of this species from seeds.

Perbedaan Indeks Plak pada Pemeriksaan dengan Bahan Disclosing Solution dan Biji Kesumba (Bixa orellana)

Dental health practitioners need to consider the use of alternative materials for the examination of plaque indexes derived from natural ingredients as a substitute for disclosing materials because they are not always available despite the high price. one example of this natural ingredient is the kesumba seed plant. The purpose of this study was to determine the differences in plaque index on examination by disclosing solution and kesumba material. This type of research is quasi-experiment. This study used a sample of 47 students from Lawulo Elementary School-aged 9-12 years, data collection was done by checking the PHP plaque index. The results showed that the average plaque index score on examination with a disclosing solution was 3.08, and the average plaque index score on examination with the examination was 2.17 with a difference of 0.91. Statistical test results obtained ρ-value: 0,000 <α (0.05) so that, it can be concluded there are differences in the plaque index on examination with Disclosing solution and examination with kesumba.