Functional Divergence of G and Its Homologous Genes for Green Pigmentation in Soybean Seeds

The degradation of chlorophyll in mature soybean seeds is closely related to the development of their yellow color. In this study, we examined G, its homologue G-like (GL), and their mutant alleles and investigated the relationship between these genes and chlorophyll accumulation in the seed coats of mature seeds. Transient expression of G and GL proteins fused with green fluorescent protein revealed that both were localized in plastids. Overexpression of G resulted in the accumulation of chlorophyll in the seed coats and cotyledons of mature seeds, indicating that high expression levels of G result in chlorophyll accumulation that exceeds its metabolism in the seeds of yellow soybean. Analysis of near isogenic lines at the G locus demonstrated a significant difference in the chlorophyll content of the seed coats and cotyledons of mature seeds when G and mutant g alleles were expressed in the d1d2 stay-green genetic background, indicating that the G protein might repress the SGR-independent degradation of chlorophyll. We examined the distribution of mutant alleles at the G and GL loci among cultivated and wild soybean germplasm. The g allele was widely distributed in cultivated soybean germplasm, except for green seed coat soybean lines, all of which contained the G allele. The gl alleles were much fewer in number than the g alleles and were mainly distributed in the genetic resources of cultivated soybean from Japan. None of the landraces and breeding lines investigated in this study were observed to contain both the g and gl alleles. Therefore, in conclusion, the mutation of the G locus alone is essential for establishing yellow soybeans, which are major current soybean breeding lines.

Serotiny in Melocactus matanzanus (Cactaceae) and role of cephalium in dispersal of seeds after the individual's death

Serotiny is a strategy in which the retention of mature seeds in parent structures allows plants to cope with environmental variability like heat, drought or fire. Although this phenomenon might be common in Cactaceae, and particularly in Melocactus, it has generally been scarcely addressed. The main goal of our work is to investigate if there are seeds hidden in the cephalium of Melocactus matanzanus and if there are, determine whether or not these seeds maintain their viability. We also discuss some advantages the cephalium may offer as diaspore after the death of individuals. Cephalia collected from dead individuals were divided into four slices and their seeds counted; we also assessed the viability and photoblastic response of the seeds by using growth chambers at 25/30°C, and by a cut test on the seeds that did not germinate. Our results showed retention of viable seeds of different ages in all slices of the cephalium. Seeds were photoblastic positive with germination between 11–22% and viability above 50% in the portion of the lots that did not germinate.

​Moringa- The Miracle Wellness Tree: A Review

Moringa [Moringa oleifera (Lam.) Moringaceae] is a fast growing, deciduous, drought tolerant and tropical perennial tree. Moringa oleifera is called as a “Miracle Tree” due to not only its nutritional and pharmacological properties but also utilized as biofuel, water purifier and cosmetic industry. Every part of Moringa oleifera is a storehouse of essential nutrients. Edible parts of the plant includes the whole leaves, immature green fruits or seed pods, flowers and roots. Mature seeds yield 38-40 per cent edible oil called ben oil. Cosmetics such as anti-ageing creams, hair care products, face creams, aromatherapy oils and massage oils use moringa oil. Fresh Moringa leaves was collected from Department of vegetable science, Kerala Agricultural University, Thrissur. The KAU Moringa variety Anupama was selected for the study during the period of 2018-2020. Moringa is indeed a miracle tree with enormous potential which is yet to be explored for therapeutic and commercial applications.

Progressive Aggregation of 16 kDa Gamma-Zein during Seed Maturation in Transgenic Arabidopsis thaliana

Prolamins constitute a unique class of seed storage proteins, present only in grasses. In the lumen of the endoplasmic reticulum (ER), prolamins form large, insoluble heteropolymers termed protein bodies (PB). In transgenic Arabidopsis (Arabidopsis thaliana) leaves, the major maize (Zea mays) prolamin, 27 kDa γ-zein (27γz), assembles into insoluble disulfide-linked polymers, as in maize endosperm, forming homotypic PB. The 16 kDa γ-zein (16γz), evolved from 27γz, instead forms disulfide-bonded dispersed electron-dense threads that enlarge the ER lumen without assembling into PB. We have investigated whether the peculiar features of 16γz are also maintained during transgenic seed development. We show that 16γz progressively changes its electron microscopy appearance during transgenic Arabidopsis embryo maturation, from dispersed threads to PB-like, compact structures. In mature seeds, 16γz and 27γz PBs appear very similar. However, when mature embryos are treated with a reducing agent, 27γz is fully solubilized, as expected, whereas 16γz remains largely insoluble also in reducing conditions and drives insolubilization of the ER chaperone BiP. These results indicate that 16γz expressed in the absence of the other zein partners forms aggregates in a storage tissue, strongly supporting the view that 16γz behaves as the unassembled subunit of a large heteropolymer, the PB, and could have evolved successfully only following the emergence of the much more structurally self-sufficient 27γz.

Masting effect on alpha and beta avian diversity in fragmented forests of relict-endangered Mexican Beech (Fagus grandifolia subsp. mexicana)

Background Tropical montane cloud forests are one of the most important hotspots on Earth and show presence of relict-endemic and endangered species, representing about 14% of the total tropical forest worldwide. Synchronous seed production or masting in tropical montane cloud tree species is a widespread reproductive strategy of deciduous and evergreen broad-leaved tree associations to decrease costs of reproduction and ensure offspring. Masting event maintains a high avian diversity, which can be modified by phenological process (seed production and non-seed production). Methods The main aim of this study was to assess alpha and beta avian diversity and whether the composition of the trophic guild modifies among phenological processes and between two fragmented relict-endangered Mexican Beech (Fagus grandifolia subsp. mexicana) forests (Medio Monte and El Gosco) in the Mexican state of Hidalgo. In addition, we evaluated beechnut production. Results We recorded 36 bird species, 11 of them included in some conservation risk status, and 5 endemic species. Alpha diversity values were dissimilar in avian richness (q = 0) among phenological processes and between fragmented beech forests. Avian communities among three phenological processes and between fragmented forests were structurally similar, dominated during immature seeds the Brown-backed Solitaire (granivores–insectivores–frugivores); during mature seeds the White-crowned Parrot (Pionus senilis, granivores–frugivores); and the Dwarf Jay (Cyanolyca nana, insectivores) was abundant during low seed quality. The complementarity index was high among phenological processes and low between forests. We found a high bird turnover value between immature seeds—mature seeds and during mature seeds—low seed quality. Furthermore, a similar pattern was recorded between the two study forests. Seed production showed a high number of undamaged beechnuts in Medio Monte, while in El Gosco beechnuts were attacked by insects. Conclusions Our results reflect that masting phenological process and contrasting study forests’ structure influence the shifts in alpha and beta diversity of seed and non-seed bird consumers. Our study reaffirms the importance of continuing studies throughout masting in all the Mexican Beech forests to address regional efforts in preserving the relict-ecological interactions.

Alkaloid Distribution in Seeds of Argemone mexicana L. (Papaveraceae)

Seeds of Argemone mexicana L. accumulate significative amounts of sanguinarine. The analysis of the distribution of this alkaloid through the tissues of mature seeds revealed that up to 60 % of its contents was found tightly fixed to the different components of the seed external covers where it persisted during seedling germination. Contrastingly, sanguinarine contents in cotyledon accounted for the remaining 40 % and it could have been, at least partially, mobilized to the newly formed hypocotyls during emergence from seeds. Berberine was only detected in immature seeds and in seedlings once cotyledons were totally displayed. These results are discussed as a possible sanguinarine role in the chemical protection during seedlings germination. Resumen. Semillas de Argemone mexicana L. acumulan cantidades elevadas de sanguinarina. Un análisis de la distribución de alcaloides en los diferentes tejidos que componen la semilla reveló que hasta un 60 % del contenido se encontraba fuertemente unido en las capas que forman la cubierta exterior, donde se retuvieron durante la emergencia del hipocótilo. En contraste, los cotiledones presentaron el 40 % restante y parte de ello pudo haber sido movilizado al hipocótilo al emerger. Berberina sólo se observó en semillas inmaduras y en plántulas en desarrollo con los cotiledones desplegados. Estos resultados se discuten en función del posible papel defensivo de la sanguinarina durante la germinación.

Effects of the growth regulators for the induction of somatic embryos from explants in an endemic and threatened Echinocactus parryi Engelm.

Introduction: The list of threatened species is enhancing and needs to be revised by integrating plant tissue culture tools with conventional techniques that support the appropriate management of these species. Objective: To assess the effects of the growth regulators for the induction of somatic embryos from mature seeds, shoots, and compact green callus of Echinocactus parryi Engelm. and the histological analysis of the embryogenic structures. Materials and methods: A completely randomized design was utilized to evaluate three types of explants (apical, medium, and basal) cultured on basal Murashige & Skoog media (MS) with different growth regulators concentrations (2, 4-D [dichlorophenoxy acetic acid], BAP [6-benzylaminopurine] and kinetin, at four levels: 0.5, 1, 1.5, and 2 mg∙L -1 ). Histological analysis of the embryogenic structures was performed. Results and discussion: The 2, 4-D induced both embryogenic and organogenic callus from seeds and shoot explants. The globular stage did not evolve to their maturity, presumably because of 2, 4-D accumulation. The compact callus explants were the more efficient to induce 19.2 somatic embryos per explant when they were cultured in the medium with 0.5 mg∙L -1 kinetin. However, the latest phases did not germinate, probably due to abnormalities generated by genetic and epigenetic changes in the DNA that can cause abnormal somatic embryos. The histology image demonstrated that the globular and torpedo structures were visible under a microscope showing stained nucleus and numerous starch grains. Conclusions: E. parryi is a species that can produce a high number of embryogenic structures, which represents a great potential to grow massive plants.

An efficient sorghum transformation system using embryogenic calli derived from mature seeds

Significant progress has been made on sorghum transformation in the last decades; however, the transformation process has been constrained by the availability of immature embryos because most of the researchers have utilized immature embryos as favorable explants. Although immature embryos have been proven to be optimal for tissue culture and transformation, isolation of immature embryos is time-consuming, labor-intensive, and limited by warm weather. In this study, we developed an efficient genetic transformation system using mature seeds as explants. The nptII and gus gene, used as the selective marker and report gene respectively, have been co-transformed by particle bombardment. After optimization of tissue culture, the G418 concentration, and transgenic, the average transformation frequency at 13.33% was achieved routinely. The transgenic events and transgene copy numbers were determined by PCR and RT-PCR, respectively. The geneticin selection and GUS staining on T1 seedlings confirmed that the transgenic plants were heritable. Our results demonstrated that the efficient sorghum transformation system has been established using mature seeds as explants. This transformation system will promote sorghum research on genetic engineering and genome editing without seasonal weather conditions restriction and explant resources restriction.

Seed morphology of Portulaca (Portulacaceae) in Cuba and taxonomic implications

Portulaca is the only genus in Portulacaceae and includes ca. 115 species with worldwide distribution. 12 species (one naturalized) occur in Cuba. The taxonomic value of seeds characters for the circumscription of species, by comparing macro- and micromorphological characters, is analyzed. The seeds of Cuban purslanes do not present association patterns between types of undulations of the anticline walls. The relief of their periclinal walls allows the corroborate certain variation in the distribution range of some species. The delimitation of Portulaca species in Cuba using seeds characters, provided as an identification key and descriptions, confirms the taxonomic value of such characters and strengthens the circumscriptions supported by the rest of the plant structures. This is largely given by the standardization of macromorphological terms with a micromorphological basis, the color of the mature seeds and their dimensions.

Transcriptomic Analysis Reveals Key Genes Involved in Oil and Linoleic Acid Biosynthesis during Artemisia sphaerocephala Seed Development

Artemisia sphaerocephala seeds are rich in polysaccharides and linoleic acid (C18:2), which have been widely used as traditional medicine and to improve food quality. The accumulation patterns and molecular regulatory mechanisms of polysaccharides during A. sphaerocephala seed development have been studied. However, the related research on seed oil and C18:2 remain unclear. For this study, A. sphaerocephala seeds at seven different development stages at 10, 20, 30, 40, 50, 60, and 70 days after flowering (designated as S1~S7), respectively, were employed as experimental samples, the accumulation patterns of oil and fatty acids (FA) and the underlying molecular regulatory mechanisms were analyzed. The results revealed that oil content increased from 10.1% to 20.0% in the early stages of seed development (S1~S2), and up to 32.0% in mature seeds, of which C18:2 accounted for 80.6% of the total FA. FA and triacylglycerol biosynthesis-related genes jointly involved in the rapid accumulation of oil in S1~S2. Weighted gene co-expression network analysis showed that transcription factors FUS3 and bHLH played a critical role in the seed oil biosynthesis. The perfect harmonization of the high expression of FAD2 with the extremely low expression of FAD3 regulated the accumulation of C18:2. This study uncovered the gene involved in oil biosynthesis and molecular regulatory mechanisms of high C18:2 accumulation in A. sphaerocephala seeds; thus, advancing research into unsaturated fatty acid metabolism in plants while generating valuable genetic resources for optimal C18:2 breeding.