Plant Emergence Research Articles

Beyond RuBisCO: convergent molecular evolution of multiple chloroplast genes in C4 plants.

BackgroundThe recurrent evolution of the C4 photosynthetic pathway in angiosperms represents one of the most extraordinary examples of convergent evolution of a complex trait. Comparative genomic analyses have unveiled some of the molecular changes associated with the C4 pathway. For instance, several key enzymes involved in the transition from C3 to C4 photosynthesis have been found to share convergent amino acid replacements along C4 lineages. However, the extent of convergent replacements potentially associated with the emergence of C4 plants remains to be fully assessed. Here, we conducted an organelle-wide analysis to determine if convergent evolution occurred in multiple chloroplast proteins beside the well-known case of the large RuBisCO subunit encoded by the chloroplast gene rbcL.MethodsOur study was based on the comparative analysis of 43 C4 and 21 C3 grass species belonging to the PACMAD clade, a focal taxonomic group in many investigations of C4 evolution. We first used protein sequences of 67 orthologous chloroplast genes to build an accurate phylogeny of these species. Then, we inferred amino acid replacements along 13 C4 lineages and 9 C3 lineages using reconstructed protein sequences of their reference branches, corresponding to the branches containing the most recent common ancestors of C4-only clades and C3-only clades. Pairwise comparisons between reference branches allowed us to identify both convergent and non-convergent amino acid replacements between C4:C4, C3:C3 and C3:C4 lineages.ResultsThe reconstructed phylogenetic tree of 64 PACMAD grasses was characterized by strong supports in all nodes used for analyses of convergence. We identified 217 convergent replacements and 201 non-convergent replacements in 45/67 chloroplast proteins in both C4 and C3 reference branches. C4:C4 branches showed higher levels of convergent replacements than C3:C3 and C3:C4 branches. Furthermore, we found that more proteins shared unique convergent replacements in C4 lineages, with both RbcL and RpoC1 (the RNA polymerase beta’ subunit 1) showing a significantly higher convergent/non-convergent replacements ratio in C4 branches. Notably, more C4:C4 reference branches showed higher numbers of convergent vs. non-convergent replacements than C3:C3 and C3:C4 branches. Our results suggest that, in the PACMAD clade, C4 grasses experienced higher levels of molecular convergence than C3 species across multiple chloroplast genes. These findings have important implications for our understanding of the evolution of the C4 photosynthesis pathway.

Studies on seed transmission of “Candidatus Liberibacter solanacearum” in pepper and its impact on plant emergence

Abstract“Candidatus Liberibacter solanacearum” (Lso), transmitted by the potato psyllid (Bactericera cockerelli), is the causal agent of potato zebra chip, but can also infect other solanaceous plants, including peppers. Studies were conducted to investigate whether Lso could be transmitted to the next generation of plants through seeds from infected pepper plants. In 2014, jalapeno pepper plants were infested with psyllids carrying a mixture of Lso A and B (AB) at the AgriLife Research Station at Bushland. The study was again conducted in 2019 and pepper plants were infested with psyllids carrying Lso B or Lso AB. In each of the studies, noninfested plants served as controls. At harvest, fruits were collected and tested for the presence of Lso using quantitative PCR. Seeds from infected fruits were then tested for Lso. Overall, the percentage of seeds that tested positive for Lso ranged from 33% to 70%. However, Lso detection in embryos ranged only from 0% to 8%. Seed samples from Lso‐positive fruits were planted in the greenhouse to determine the impact of Lso on emergence and the incidence of Lso in emerged plants. Although plant emergence differed between some of the seeds obtained from Lso‐positive and ‐negative fruits, the overall impact of Lso on plant emergence was not consistent. However, of the 182 plants that emerged from seeds collected from infected fruits, none was positive for Lso, suggesting that seeds are unlikely to serve as sources for new Lso infections and their impact on disease epidemiology is negligible.

Interactions among cereal cyst nematode Heterodera filipjevi, dryland crown rot Fusarium culmorum, and drought on grain yield components and disease severity in bread wheat

The cereal cyst nematode (CCN) Heterodera and crown rot caused by Fusarium species limit cereal production and yield potential. Losses increase when CCN and crown rot occur together, especially under water stress conditions. The objective of this study was to investigate the interactions among Heterodera filipjevi, Fusarium culmorum, and drought on a set of wheat germplasm with differing levels of resistance/tolerance to CCN, crown rot and drought. Plant emergence was significantly reduced (56% seedling death) when seeds were planted in a water stress environment where F. culmorum and H. filipjevi were present. Crown rot was more severe under water stress compared with Fusarium inoculation alone. The number of cysts fell significantly when H. filipjevi was co-inoculated with F. culmorum, revealing an antagonistic interaction between the nematode and fungus. The highest number of cysts was found on the susceptible accession ‘Seri’ under water stress conditions. Water stress caused a significant reduction in plant height, while F. culmorum inoculation did not, unless combined with water stress. Yield components were significantly reduced by each of the single stresses and losses were greater when plants were exposed to double or triple stresses. Water stress and F. culmorum inoculation caused a significant reduction in spike weight and seeds per spike. The chlorophyll content of wheat leaves was negatively affected by water stress and inoculation by both nematode and fungus. In conclusion, water stress exacerbates the damage caused by CCN and crown rot, and planting drought-resistant varieties would be an ideal solution to reduce losses.

Decomposing complex traits through crop modelling to support cultivar recommendation. A proof of concept with a focus on phenology and field pea

Cultivar recommendation is crucial for achieving high and stable yields, and crop models can successfully support it because of their capability of exploring genotype environment management interactions. Different modelling approaches have been developed to this end, primarily relying on dedicated field trials to characterize the germplasm of interest. Here, we show how even data routinely collected in operational contexts can be used for model-based cultivar recommendation, with a case study on phenological traits and field pea (Pisum sativum L.). Eight hundred and four datasets, including days from sowing to plant emergence, first flower, and maturity, were collected in Northern Italy from 2017 to 2020, and they were used to optimise six parameters (base, optimum, and maximum temperature for development, growing degree days to reach emergence, flowering, and maturity) of the crop model WOFOST-GT2 for 13 cultivars. This allowed obtaining the phenotypic profiles for these cultivars at the level of the functional trait, without the need of carrying out dedicated phenotypisations. Sensitivity analysis (SA) techniques (E-FAST) and the statistical distributions of the optimised parameters were used to design pea ideotypes able to maximise yields and yield stability in 24 agro-climatic contexts (three soil conditions two sowing times four agro-climatic classes). For each context, the 13 cultivars were ranked according to their similarity to the ideotype based on the weighted Euclidean distance. Results of SA identified growing degree days to reach flowering as the trait mainly affecting crop productivity, although cardinal temperatures also played a role, especially in the case of early sowings. This is reflected in the ideotypes and, therefore, in cultivar ranking, leading to recommend a panel of cultivars characterised by low base temperature and high thermal requirements to reach flowering. Despite the limits of the study, which is focused only on phenological traits, it represents an extension of available approaches for model-aided cultivar recommendation, given that the methodology we propose can take full advantage of the potentialities of crop models without requiring dedicated experiments aimed at profiling the germplasm of interest at the level of functional traits. Highlights- Crop models are powerful tools to support cultivar choice by exploring genotype x environment x management interactions.- Crop models require cultivar-specific phenotyping data at the level of functional traits.- We propose a methodology that uses data routinely collected in operational contexts to derive functional trait values.- This study is a proof of concept of how to increase the applicability of model-based approaches for cultivar choice.

Humik Asit Uygulamalarının Zambak Bitkisinin Gelişimi, Bitkideki Fenolojik ve Pomolojik Gözlemler Üzerine Etkisi

In this study, a pot study was carried out to reveal the effects of direct and foliar applications of humic acid to the growing medium in addition to basic fertilization on the development and plant quality characteristics of lily plants grown in peat + perlite medium. The experiment was carried out in an unheated greenhouse during the summer, in a greenhouse environment with a shade net on it. In the experiment, in addition to the control, the humic acid doses were 3.5 lt/da from soil, 7.5 lt/da from soil, 1.75 lt/da from leaf, 3.75 lt/da from leaf and soil + 3.5 lt/da from leaf + 1, It was applied 3 times as 75 lt/da. In the pot experiment established in three replications according to the randomized plots trial design, 10 lily bulbs were planted in each pot and humic acid applications were made at two-week intervals following plant emergence. In order to see the effect of the applications when the plant is harvested, the length of the flower stem (mm), the thickness of the flower stem (mm), the fresh weight of the branch (mm), the number of buds (pieces), the bud length (cm), the number of leaves (pieces), Full bloom stem (mm) and vase life (days) were examined. As the doses of humic acid increased, the vegetative weight of the lily plant increased, while the effect of the applications on the investigated properties was different. With the mineral elements, hormones and plant growth regulators in humic acid, it has the feature of promoting the increase of biomass in the plant.

Ajuste da densidade de semeadura de arroz pelo vigor de sementes

ABSTRACT The use of high-vigor seeds combined with seeding density adjustment at sowing is speculated to ensure high yields. However, certain doubts regarding the effect of this combined approach on rice cultivation remain owing to the tillering capacity. In this context, the present study aimed to determine the effects of seeding density adjustment according to vigor on the initial establishment of seedlings in the field. A physiological characterization was conducted using the germination test, vigor by accelerated aging, electrical conductivity, first count, shoot length, root length, total seedling length, and dry mass in the 2019/2020 and 2020/2021 growing seasons. The evaluations were conducted using a completely randomized design with four replications. Subsequently, the seed lots were selected, from which a fraction of seeds were submitted to artificial vigor reduction. Afterward, these seeds were sown in the main producing regions of the state of Santa Catarina, under a randomized block design with four replications. Three treatment groups were formed: one without density adjustment, one with adjustment by germination, and one with adjustment by vigor in accelerated aging. Twenty-one days after sowing, the number of emerged seedlings per unit area was determined. An interaction between the factors of adjustment for density and seed quality was observed. This was evidenced in the fact that even with the adjustment of density by vigor, the seed lot with lower quality presented the emergence of a lower number of seedlings, and the performance of these seeds was not equivalent to that observed in the lot with superior quality. Accordingly, it was concluded that the seeding density adjustment by vigor combined with the use of seeds with high-vigor is a suitable strategy for achieving a significant increase in plant emergence during the initial establishment in the field.

Investigation of induction motor operation from the soft starter in reverse mode with reduced speed

Ease of maintenance and high reliability of asynchronous electric drives actively popularize their using in manufacturing. At the same time, such drive has its drawbacks: high currents and significant torque during direct starting from contactor control systems. This problem can be solved using the so-called "service functions" of soft starters. This work at developing these functions and issuing recommendations for their use is aimed. The purpose of the investigation is to determine the possibility of using the "service functions" of soft starters for emergency and service modes of agricultural plants. The investigation of the operation of an induction motor with a soft starter using the provisions of the theory of electrical circuits of sinusoidal and non-sinusoidal currents and using computer analysis was carried out. Investigation on the mechanism of straw shredders using a soft starter was carried out. Performance increasing of such a mechanism is possible using the "reverse" function with a reduced speed, implemented, for example, in SSW900 soft starters. To configure the soft starter, the WEG programming Suite software was used, which, in addition to the function of writing parameters, also contains the function of reading parameters and visualizing them as trends. As a result of the investigation, it was found that the intelligent control of thyristors in soft starters allows to expand their functionality, namely, to reverse the induction motor without using an additional contactor. The implementation of the reverse speed function with appropriate restrictions in soft starters allows reducing the cost of the used electrical equipment for straw shredders. Too much JOG relative voltage to the soft starter can cause large fluctuations in motor speed and must be carefully adjusted.

A Bi-Level Scheduling Model of the Distribution System With a Distribution Company and Virtual Power Plants Considering Grid Flexibility

With the emergence of virtual power plants (VPPs) in distribution systems, distribution companies (DISCOs) can manage distributed generators scattered across their systems. Interactions between each DISCO and VPP are expected to be crucial for securing system reliability without increasing operational complexity. This article proposes a bi-level scheduling model for these interactions, considering the ramping flexibility of the distribution system. In the upper level, the DISCO minimizes the distribution system’s operational cost and the cost of procuring flexibility by varying the price of the power traded with the VPP. In the lower level, the VPP maximizes its profit by managing the amount of power it trades with the DISCO. We transform the bi-level model into a single-level problem by using Karush–Kuhn–Tucker optimality conditions and linearization techniques. We present case studies of interactions between the DISCO and VPPs, with the assumption that the DISCO can purchase active power from a wholesale market. The results demonstrate that a win–win situation for both the DISCO and VPP can be achieved by managing the power exchanged while procuring flexibility.

RUSSELL REVIEW Are plant roots only “in” soil or are they “of” it? Roots, soil formation and function

AbstractRoots are near‐ubiquitous components of soils globally but have often been regarded as separate from the soil rather than a substantial factor in determining what soil is and how it functions. The start of rapid soil formation commenced about 400 million years ago with the emergence of vascular plants and the evolution of roots and associated microbes. Roots and associated microorganisms contribute significantly to soil formation by altering rocks and soil minerals through a variety of biogeochemical processes and supply carbon to a depth that can have long residence times. Living root inputs of carbon via rhizodeposits are more efficient than shoot and root litter inputs in forming slow‐cycling, mineral‐associated soil organic carbon pools. The current functionality of soils in providing food and fuel and fibres, supplying plant nutrients, filtering water and flood regulation, and disease suppression are all dependent on the activities of plant roots. Roots are actively communicating and collaborating with other organisms for mutual benefit, and the signals underlying this modulation of the rhizosphere microbiome are being identified. In this review I examine how plant roots (an organ not an organism) affect soil formation and function and conclude that, from several perspectives, roots are not just “in” soil but “of” it and that definitions of soil should recognise this. A possible definition is: “Soils are altered surficial rock or sediment, composed of organic matter, minerals, fluids, and organisms whose formation and functionality are influenced by biogeochemical weathering and interactions of these components with plant roots.”HighlightsPaleoclimatic and paleosoil research shows the key role of roots and mycorrhiza in soil formation.Deep roots and living root inputs are substantial contributors to long‐term C storage.Root/microbe signalling facilitates mutualistic symbioses, nutrient uptake and disease suppression.Definitions of soil should explicitly include roots as an important component of the soil system.

The evaluation of planter downforce on emergence and grain yield in soybean

AbstractPlanter downforce could unify crop emergence by maintaining uniform seeding depth while planting. This research was conducted to determine if planter downforce rate impacted soybean [Glycine max (L.) Merr.] emergence and grain yield in South Carolina. The effects of tillage type, gauge wheel width, and downforce rate (0–300 lbf in 50‐lbf increments) on soybean were evaluated at the Edisto (EREC) and Piedmont (PREC) Research and Education Centers in South Carolina. At EREC, a downforce rate over 200 lbf resulted in decreased plant emergence compared with 0, 50, 100, and 150 lbf. A downforce rate of 0 and 50 lbf had a reduced number of emerged plants at 2, 3, and 4 d after emergence compared with rates over 150 lbf at PREC. As downforce rate increased, the depth at which seed were planted increased up to 35% of the original planting depth at EREC. Planter downforce rate appears to influence overall soybean emergence. However, uniform emergence in soybean does not appear to impact grain yield in these production scenarios in South Carolina.

EVALUATION OF FUNGICIDAL POTENTIAL OF TWENTY MEDICINAL PLANTS AGAINST MACROPHOMINA PHASEOLINA CAUSING CHARCOAL ROT OF GREEN GRAM

The possible use of plants with antifungal activities for the control of Macrophomina phaseolina is an area that has not been fully exploited. The objective of the present study was, therefore, to evaluate twenty antagonistic plants found in the country for their antifungal activity against M. phaseolina, as no information is available on the antifungal activities of these plants against the fungus. All the test plants when used as seed treatment, significantly enhanced seedling emergence (P 0.001). Of all the test plants, Azadirachta indica showed the maximum increase in emergence of black gram (58.33%) over control followed by Nigella sativa (57.50%) and Carum copticum (51.67%). On the other hand, Nicotiana tabacum, Foeniculum vulgare and Lawsonia inermis appeared to be the least effective in reducing the damage of the pathogen showing 30, 30.83 and 32.5% increases in emergence. The maximum individual increase in seedling emergence of black gram (73.33%) was attained with 10% concentration of A. indica. The minimum of 20% increase in plant emergence was obtained with F. vulgare at 1% concentration. Other plants showed intermediate increases in seedling emergences. Significant effects (P 0.001) of concentrations were also observed on seedling emergence. Maximum seedling emergence was recorded at 10% concentration of decoctions of test antagonistic plants. As the concentration of medicinal plants decreased, the effects on seedling emergence also decreased. The effect of concentrations was found to be directly proportional to seedling emergence.

Agro-Morphological Characterization and Some Seed Characteristics of Wild Crambe (Brassicaceae) Species in Turkey

The seeds of wild Crambe species have potential to be used as a source of industrial oil and animal feed. In this study, 48 genotypes of three Crambe species collected from the flora of Turkey were grown under field conditions in Ankara/Turkey in 2014–2016. The seed protein ratio, plant height, number of branches per plant, number of seeds per plant, seed yield per plant, thousand seed weight and hulless/hulled seed ratio (H/H) were determined. The highest protein ratio was determined as 26.02% in the t18 accession of Crambe tataria species. Variations in the characteristics were analyzed using principal component analysis. In the factor analysis of Crambe maritima, Crambe orientalis, Crambe tataria and the mean of these three species, the first two principal components accounted for 100%, 58.06%, 59.93% and 100% of the total variations, respectively. There were positive correlations between the plant height and number of seeds per plant, seed yield per plant for C. orientalis, and number of branches per plant for C. tataria. Although seed yield per plant was high in C. tataria and C. orientalis, they are not suitable for conventional agriculture due to shell thickness, inhomogeneous plant emergence and shooting. Conventional cultivation of wild Crambe species can be made possible by eliminating these negative features with breeding and agronomic studies.

Effect of Salicylic Acid Foliar Application on Two Wheat Cultivars Grown under Zinc Stress

The aim of this study was to investigate the effect of foliar application of salicylic acid (SA) on alleviating Zn stress in young wheat plants. Two rigorous pot experiments were conducted with two spring wheat cultivars growing on soil artificially contaminated with Zn. The experimental design included three levels of soil contamination with Zn: 0, 300 and 700 mg kg−1, and three levels of SA concentration: 0, 0.5 and 1 mM. Foliar spray of SA was applied twice at an interval of two weeks. Wheat biomass was harvested two months after plant emergence. Both cultivars showed similar biomass reduction due to Zn phytotoxicity, but differed in the accumulation and distribution of this metal in the plant. The positive effect of SA foliar application was obtained only for one of the two tested cultivars, where a reduction in the Zn translocation from the roots to the aboveground part was observed. As a consequence, the decrease in biomass caused by the toxicity of Zn was limited. A greater positive effect of SA application on wheat biomass was observed at 700 than at 300 mg kg−1 Zn in soil. The different responses of the cultivars to the SA was probably related to their different defense mechanisms against Zn stress.

ESTIMATION OF DENSITY OF SPRING BARLEY PLANTS DEPENDING ON TECHNOLOGICAL TECHNIQUES OF GROWING

During the research period, the impact of fertilizers and foliar fertilization on the indicators of germination and preservation of spring barley plants was assessed. The obtained research results indicate the dependence of these indicators on mineral fertilizers and foliar fertilization. As mineral fertilizers promote seed germination and intensify the processes of growth and development of spring barley plants, improve the development of the root system, moisture absorption, as well as the efficiency of assimilation of macro- and micronutrients. Conducting foliar fertilization can improve the supply of mineral nutrients in critical periods of growth and development, which has a positive effect on the bookmark and formation of generative organs, plant resistance to disease, stress resistance of plants at high temperatures, drought, increases photosynthetic activity and increases and the quality of the grain harvest. Field germination was influenced by soil temperature and humidity during seed germination and fertilization system. The highest field similarity in the varieties Aizhan (84.1%) and Aristei (83.3%) was observed in the variants of the experiment, where mineral fertilizers were applied at a dose of N30P30K30, which is 1.2% more, respectively. The density of plants in the phase of full germination, depending on the variety, varied in the range of 328.4-336.8 pieces / m2 and differed insignificantly according to the variants of the experiment. Preservation of spring barley plants, depending on the study option, varied from 77.4 to 81.7%.In the variant of studies for the application of mineral fertilizer at a dose of N30P30K30, the preservation of plants was in the variety Aizhan - 79.8% and in the variety Aristei - 79.0%, which is higher than the control by 1.9 and 1.6% or 10.1 and 9.2 pcs / month With the joint application of mineral fertilizer at a dose of N30P30K30 and foliar fertilization of plants with the biological product Yara Vita in the phase of emergence of plants in the tube and in the phase of earing in varieties Aijan and Aristei plant survival was 81.4 and 81.5%; 81.3 and 81.3%, which is higher than the control by 3.5 and 3.6% and 3.9 and 3.9%. With the joint application of mineral fertilizer at a dose of N30P30K30 and foliar feeding of plants with microfertilizer Vuxal in the phase of plant emergence in the tube and in the phase of earing in varieties Aijan and Aristei plant survival was 81.6 and 81.7%; 81.4 and 81.5%, which is higher than the control by 3.7 and 3.8 and 4.0 and 4.1% or 16.2 and 16.7 and 17.1 and 17.5 units / м².

Seed treatment for managing fall armyworm as a defoliator and cutworm on maize: plant protection, residuality, and the insect life history.

The highly polyphagous and invasive fall armyworm (FAW, Spodoptera frugiperda) can feed on different plant parts of host crops, damaging whorls and stalks in early maize growth stages. Systemic insecticide seed treatment (IST) could minimize this damage, although the residual efficacy may vary with the plant tissue damaged. Using damage rating scales and artificial infestation in controlled conditions, we determined the potential of IST against FAW attacking maize whorl leaves or the stalk base. Chlorantraniliprole, cyantraniliprole, or thiodicarb + imidacloprid IST similarly killed > 80% FAWs for 1 or 2 weeks after plant emergence depending on the plant tissue attacked. The residual efficacy (i.e. time after plant emergence sustaining > 80% larval mortality) lasted from the first to the eleventh day (VE-V3 maize growth stages), while for cutworm on the maize stalk base, it lasted 3-7 days after plant emergence (V1-V2 stages). In terms of damage, the ISTs lasted 15 days after emergence (V4 stage) for FAW on whorl leaves and 10 days (V3 stage) for FAW feeding on the stalk base. The larvae surviving on the seed-treated plants underwent sublethal effects in growth and development, reducing insect fitness. Diamide or carbamate + neonicotinoid seed treatments kill FAW larvae on maize whorls or stalks in favorable edaphoclimatic and insecticide-susceptibility conditions. The cumulative impacts of systemic IST on aboveground insect pests go beyond mortality. The ISTs studied can be valuable against FAW in maize, for instance, to help protect varieties that may not express sufficient insect resistance in maize early growth stages.

Seeding System Configuration Effects on Sunflower Seedling Emergence and Yield under No-Tillage

No-tillage farming can improve crop productivity and the reliability of cropping compared with conventional tillage. The effects of three different seeding system configurations on surface residue handling, sunflower emergence and stand establishment, yield, and gross income were investigated over three cropping seasons. The seeding system configurations comprised of (1) turbo coulter blade, (2) notched disc row cleaner before turbo coulter blade, and (3) no residue handling unit installed in front of a double-disc opener. For all three seeding system configurations, crop residue cover on sown rows (after seeding) was greater than the minimum recommended value of 30% for no-tillage. Residue cover was best with the notched disc row cleaner in front of the turbo coulter blade compared to the other two seeding systems. Furthermore, the notched disc row cleaner in front of the turbo coulter blade produced the highest plant emergence counts and the most uniform stand establishment. Sunflower yield and gross income were highest with the notched disc row cleaner in front of the turbo coulter blade (3.16 Mg·ha−1 and 902 USD·ha−1) compared to when only the turbo coulter blade (2.38 Mg·ha−1 and 680 USD·ha−1) or no residue handling unit (1.69 Mg·ha−1 and 482 USD·ha−1) was used.

Origin, evolution and diversification of plant ARGONAUTE proteins.

Argonaute (AGO) proteins are central players in RNA interference in eukaryotes. They associate with small RNAs (sRNA) and lead to transcriptional or posttranscriptional silencing of targets, thereby regulating diverse biological processes. The molecular and biological functions of AGO proteins have been extensively characterized, particularly in a few angiosperm species, leading to the recognition that the AGO family has expanded to accommodate diverse sRNAs thereby performing diverse biological functions. However, understanding of the expansion of AGO proteins in plants is still limited, due to a dearth of knowledge of AGO proteins in green algal groups. Here, we identified more than 2900 AGO proteins from 244 plant species, including green algae, and performed a large-scale phylogenetic analysis. The phylogeny shows that the plant AGO family gave rise to four clades after the emergence of hydrobiontic algae and prior to the emergence of land plants. Subsequent parallel expansion in ferns and angiosperms resulted in eight main clades in angiosperms: AGO2, AGO7, AGO6, AGO4, AGO1, AGO10a, AGO10b and AGO5. On the basis of this phylogeny, we identified two novel AGO4 orthologs that Arabidopsis does not have, and redefined AGO10, which is composed of AGO10a and AGO10b. Finally, we propose a hypothetical evolutionary model of AGO proteins in plants. Our studies provide a deeper understanding of the phylogenetic relationships of AGO family members in the green lineage, which would help to further reveal their roles as RNAi effectors.

Oviposition behaviour and emergence through time of the small blue butterfly (Cupido minimus) in a nature reserve in Bedfordshire, UK

Climate change affects butterflies in many ways, influencing the timing of emergence and reproduction, habitat preferences, and behaviour. The small blue (Cupido minimus Fuessley, 1775) is highly specialised in its host plant requirements, feeding on the seeds of a single species, kidney vetch (Anthyllis vulneraria), on which the larvae occur singly to avoid cannibalism. The butterfly is likely to be vulnerable to temperature-related changes in oviposition, adult emergence, and host plant flowering times, and is, therefore, a good model species for investigating climate change-related impacts. Using 26 years of data from the national UK Butterfly Monitoring Scheme (1993–2019) from one nature reserve, and 4 years of targeted egg searches (2006, 2007, 2008, 2020) from three reserves in Bedfordshire, UK, we investigated the effects of local temperature on small blue emergence date and total abundance, whether flowerhead or local environmental characteristics predicted small blue oviposition behaviour, and whether this changed between years. Small blue adults emerged on earlier dates over time, and earlier in years with higher maximum February temperatures. Total adult abundance was not predicted by monthly temperatures or total abundance in the previous year. Oviposition behaviour was broadly consistent across years, with egg presence more likely and egg abundance higher on kidney vetch flowerheads that were taller than the surrounding vegetation, and surrounded by taller vegetation and fewer mature flowerheads. The effect of solar radiation differed between years, with a negative effect on the probability of egg presence in 2007 and 2008, but a positive effect in 2020. Egg abundance per flowerhead was highly variable between years, with 2006 having four times more eggs per flowerhead than other years. This was likely driven by high adult abundance in 2006, which could have increased competition for flowerheads.Implications for insect conservationOur results indicate that management for greater availability of taller kidney vetch amongst taller vegetation would encourage small blue oviposition on a greater number of flowerheads, providing a possible means of reducing competition and increasing larval survival, and that this would be effective despite variation in adult abundance between years. The high level of competition we observed in the year with the highest adult abundance indicates that higher numbers of host plants should be encouraged to reduce competition and larval cannibalism in peak years, increasing the likelihood of long-term population persistence and growth.

CORN CULTIVATION (BRS 2022) SUBMITTED TO NPK MINERAL FERTILIZATION AND SOIL CONDITIONING BACTERIA

The corn crop is of great importance for Brazilian agriculture and can be influenced by several factors that interfere in the final productivity, among which the correct management of soil fertility stands out, carrying out a correct fertilization to achieve a high yield. The objective of this work was to evaluate the development and productivity of maize subjected to different doses of phosphorus, potassium and nitrogen, constant, and to evaluate the effect of inoculating seeds with phosphorus and potassium solubilizing and N-fixing bacteria. conducted in the experimental area of the Center for Agricultural Sciences at the Federal University of Campina Grande (UFCG) (CCTA), in – PB. The experiment was in randomized blocks, with 10 treatments and 6 replications, the treatments corresponded to the combinations of NPK mineral fertilizer with doses of 0%, 50% and 100% of the crop need and soil conditioning bacteria AzotoBarvar-1® fixing bacteria nitrogen, PhosphoBarvar-2® bacteria with phosphorus solubilizing action and PotaBarvar-2® bacteria with potassium solubilizing action. T1 = Control (without mineral fertilizer and soil conditioning bacteria); T2 = with 100% of the mineral fertilizer recommended for the crop; T3 AzotoBarvar-1® with addition of 100% PK; T4 = AzotoBarvar-1® with addition of 50% nitrogen plus 100% PK; T5 = PotaBarvar-2® with addition of 100% NP; T6 = PotaBarvar-2® with addition of 50% potassium plus 100% NP; T7 = PhosphoBarvar-2® with addition of 100% NK; T8 = PhosphoBarvar-2® with addition of 50% phosphorus plus 100% NK; T9= Nitrogen Barvar-2®; PotaBarvar-2®; PhosphoBarvar-2®; T10= Nitrogen Barvar-1®; PotaBarvar-2®; PhosphoBarvar-2® with addition of 50% NPK. Plants were grown in pots with a capacity of 45 dm3 for 59 days, mean plant height (ALP) and leaf length (CF) 28 days after plant emergence and Leaf number (NF) 5 days after emergence of plants submitted to NPK fertilization and soil conditioning bacteria, 49 days after germination. Where there was interaction between treatment and cultivar. During this period, the plants were evaluated for growth, dry matter accumulation and production. The association of soil conditioning bacteria, with a dose of 50% fertilization with NPK, which promoted greater ear size, production and height of maize plants when compared to the treatment without bacterial inoculation. It is concluded that the highest values obtained for the growth and physiological parameters were observed in the treatments in which the soil conditioning bacteria via seeds and fertigation were used.

SOG1, a plant-specific master regulator of DNA damage responses, originated from nonvascular land plants.

The suppressor of gamma response 1 (SOG1), a NAM, ATAF1, 2, and CUC2 (NAC)‐type transcription factor found in seed plants, is a master regulator of DNA damage responses (DDRs). Upon DNA damage, SOG1 regulates the expression of downstream DDR genes. To know the origin of the DDR network in land plants, we searched for a homolog(s) of SOG1 in a moss Physcomitrium (Physcomitrella) patens and identified PpSOG1a and PpSOG1b. To assess if either or both of them function(s) in DDR, we knocked out the PpSOG1s using CRISPR/Cas9‐mediated gene editing and analyzed the responses to DNA‐damaging treatments. The double‐knockout (KO) sog1a sog1b plants showed resistance to γ‐rays, bleomycin, and ultraviolet B (UVB) treatments similarly seen in Arabidopsis sog1 plants. Next, we irradiated wild‐type (WT) and KO plants with γ‐rays and analyzed the whole transcriptome to examine the effect on the expression of DDR genes. The results revealed that many P. patens genes involved in the checkpoint, DNA repair, replication, and cell cycle‐related genes were upregulated after γ‐irradiation, which was not seen in sog1a sog1b plant. These results suggest that PpSOG1a and PpSOG1b work redundantly on DDR response in P. patens ; in addition, plant‐specific DDR systems had been established before the emergence of vascular plants.