Anthracnose, induced by Colletotrichum gloeosporioides, poses a substantial economic threat to rubber tree yields and various other tropical crops. Ede1, an endocytic scaffolding protein, plays a ...crucial role in endocytic site initiation and maturation in yeast. Metacaspases, sharing structural similarities with caspase family proteases, are essential for maintaining cell fitness. To enhance our understanding of the growth and virulence of C. gloeosporioides, we identified a homologue of Ede1 (CgEde1) in C. gloeosporioides. The knockout of CgEde1 led to impairments in vegetative growth, conidiation, and pathogenicity. Furthermore, we characterized a weakly interacted partner of CgEde1 and CgMca (orthologue of metacaspase). Notably, both the single mutant ΔCgMca and the double mutant ΔCgEde1/ΔCgMca exhibited severe defects in conidiation and germination. Polarity establishment and pathogenicity were also disrupted in these mutants. Moreover, a significantly insoluble protein accumulation was observed in ΔCgMca and ΔCgEde1/ΔCgMca strains. These findings elucidate the mechanism by which CgEde1 and CgMca regulates the growth and pathogenicity of C. gloeosporioides. Their regulation involves influencing conidiation, polarity establishment, and maintaining cell fitness, providing valuable insights into the intricate interplay between CgEde1 and CgMca in C. gloeosporioides.
In Chile, the main Coleopteran species of stored grains are Sitophilus oryzae, S. zeamais, and S. granarius. The aim of this study was to evaluate under laboratory conditions the contact and fumigant ...insecticidal activity, as well as the repellent and antifeedant effects of Laureliopsis philippiana (Looser) Schodde essential oil against adults of Sitophilus spp. The main compounds identified in this essential oil were methyleugenol (61.38%) and safrole (14.76%). Based on the contact bioassay, the highest toxicity was achieved with the concentration of 4.0% (v/w), and S. oryzae was the most susceptible species. Emergence (F1) was reduced as the concentration of the essential oil increased, reaching maximums of 60% in the case of S. granarius and S. oryzae, and 36% in S. zeamais. Mortality by fumigant activity was 100% for the three species of Sitophilus. All of the treatments had a repellent effect. The highest antifeedant activity (82.9%) was recorded at 4.0% (v/w) concentration. Concentrations below 2.0% (v/w) did not affect germination of maize. Based on these results, L. philippiana essential oil has the potential to control Sitophilus spp. weevils.
Uno de los aspectos importantes a considerarse en la producción eficiente de plántulas con fines de restauración es la calidad de semillas y su variabilidad. El obj etivo de este estudio fue evaluar ...los parámetros de semillas de acuerdo con las reglas del "International Seed Testing Association" entre diferentes árboles madre o individuos de siete especies nativas (Cedrela montana, Morella pubescens, Inga acreana, Tabebuia chrysantha, Ocotea heterochroma, Oreocallis grandiflora y Myrcianthes rhopaloides) en dos bosques de montaña del sur del Ecuador. Estas especies fueron seleccionadas por la importancia ecológica, socioeconómica, y su gran potencial para la restauración. De un total de 35 árboles madre de todas las especies, se colectaron las semillas en sus respectivos periodos de fructificación, y en el laboratorio fueron analizados los siguientes parámetros: pureza, peso, contenido de humedad y germinación; adicionalmente se determinó el coeficiente de velocidad de germinación. Los resultados mostraron una similitud intraespecífica en cada especie para la mayoría de los parámetros; no obstante, el peso presentó alta variabilidad intraespecífica para todas las especies. El parámetro germinación obtuvo diferencias entre individuos para C. montana, T. chrysantha, O. heterochroma y M. rhopaloides. En cuanto a la velocidad de germinación, individuos de especies como O. grandiflora e I. acreana mostraron un alto coeficiente en contraste a los individuos de O. heterochroma y M. pubescens. La información generada en este estudio podría ser el primer paso en la formulación de pautas para la producción masiva de plántulas de especies nativas con fines de restauración.
SUMMARY
DELAY OF GERMINATION 1 is a key regulator of dormancy in flowering plants before seed germination. Bryophytes develop haploid spores with an analogous function to seeds. Here, we investigate ...whether DOG1 function during germination is conserved between bryophytes and flowering plants and analyse the underlying mechanism of DOG1 action in the moss Physcomitrium patens. Phylogenetic and in silico expression analyses were performed to identify and characterise DOG1 domain‐containing genes in P. patens. Germination assays were performed to characterise a Ppdog1‐like1 mutant, and replacement with AtDOG1 was carried out. Yeast two‐hybrid assays were used to test the interaction of the PpDOG1‐like protein with DELLA proteins from P. patens and A. thaliana. P. patens possesses nine DOG1 domain‐containing genes. The DOG1‐like protein PpDOG1‐L1 (Pp3c3_9650) interacts with PpDELLAa and PpDELLAb and the A. thaliana DELLA protein AtRGA in yeast. Protein truncations revealed the DOG1 domain as necessary and sufficient for interaction with PpDELLA proteins. Spores of Ppdog1‐l1 mutant germinate faster than wild type, but replacement with AtDOG1 reverses this effect. Our data demonstrate a role for the PpDOG1‐LIKE1 protein in moss spore germination, possibly alongside PpDELLAs. This suggests a conserved DOG1 domain function in germination, albeit with differential adaptation of regulatory networks in seed and spore germination.
Significance Statement
Seed and spore germination are considered analogous because they occur in the sporophyte (seed plants) and gametophyte (bryophytes). Here we show that an ortholog of Arabidopsis DELAY OF GERMINATION 1 (DOG1) controls spore germination in the moss P. patens, suggesting deep evolutionary conservation of germination control of reproductive diaspores.
Seed dormancy is an innate seed property that defines the environmental conditions in which the seed is able to germinate. It is determined by genetics with a substantial environmental influence ...which is mediated, at least in part, by the plant hormones abscisic acid and gibberellins. Not only is the dormancy status influenced by the seed maturation environment, it is also continuously changing with time following shedding in a manner determined by the ambient environment. As dormancy is present throughout the higher plants in all major climatic regions, adaptation has resulted in divergent responses to the environment. Through this adaptation, germination is timed to avoid unfavourable weather for subsequent plant establishment and reproductive growth. In this review, we present an integrated view of the evolution, molecular genetics, physiology, biochemistry, ecology and modelling of seed dormancy mechanisms and their control of germination. We argue that adaptation has taken place on a theme rather than via fundamentally different paths and identify similarities underlying the extensive diversity in the dormancy response to the environment that controls germination.
Nitrogen fixation is crucial for plants as it is utilized for the biosynthesis of almost all biomolecules. Most of our atmosphere consists of nitrogen, but plants cannot straightforwardly assimilate ...this from the air, and natural nitrogen fixation is inadequate to meet the extreme necessities of global nutrition. In this study, nitrogen fixation in water was achieved by an AC-driven non-thermal atmospheric pressure nitrogen plasma jet. In addition, Mg, Al, or Zn was immersed in the water, which neutralized the plasma-treated water and increased the rate of nitrogen reduction to ammonia due to the additional hydrogen generated by the reaction between the plasma-generated acid and metal. The effect of the plasma-activated water, with and without metal ions, on germination and growth in corn plants (
) was investigated. The germination rate was found to be higher with plasma-treated water and more efficient in the presence of metal ions. Stem lengths and germination rates were significantly increased with respect to those produced by DI water irrigation. The plants responded to the abundance of nitrogen by producing intensely green leaves because of their increased chlorophyll and protein contents. Based on this report, non-thermal plasma reactors could be used to substantially enhance seed germination and seedling growth.
In an effort to induce genetic variations and identify commercially useful variants of snapdragon, seeds of a proprietary snapdragon line OAK564 were treated with different levels (0, 0.10, 0.25, ...0.5, 0.75, and 1.0%) of ethyl methanesulfonate (EMS) for three time durations (8, 10, and 12 h). Significant differences were observed for seed germination at 0.25% and 1% EMS, as well as for 0.25% EMS x 8 h and 1% EMS x 12 h treatment combinations. Although there were no significant differences among all EMS treatments and time durations for plant survival, significant differences were observed among EMS treatments and time durations for pollen viability. Based on these findings, a large-scale mutagenesis experiment was conducted using 2000 seeds of line OAK564 treated with either 0.50, 0.75, or 1.0% EMS for 10 h. Germinating seedlings (M.sub.1) were evaluated for various phenotypic traits. Several useful alterations in all three M.sub.1 populations were observed for plant architecture (dwarfing, multiple branching, and secondary branching), plant color (chlorophyll chimeras, yellowish-green tissues, and dark green tissues), leaf morphology (small leaf size, leaf curling, wavy leaf margins, and thickened striations), and floral morphology (rolled petals, elongated petals, and curtailed petals). Thus, EMS treatments induced various mutations for various phenotypic traits, thereby increasing the genetic diversity in these M.sub.1 snapdragon populations.
PDF
