Abstract Cytoplasmic male sterility (CMS) is a maternally inherited trait that derives from the inability to produce functional pollen in higher plants. CMS results from recombination of the mitochondrial genome. However, understanding of the molecular mechanism of CMS in pepper is limited. In this study, comparative transcriptomic analyses were performed using a near-isogenic CMS line 14A (CMS-14A) and a maintainer line 14B (ML-14B) as experimental materials. A total of 17,349 differentially expressed genes were detected between CMS-14A and ML-14B at the PMC meiosis stage. Among them, six unigenes associated with CMS and 108 unigenes involved in energy metabolism were identified. The gene orf165 was found in CMS-14A. When orf165 was introduced into ML-14B, almost 30% of transgenic plants were CMS. In addition, orf165 expression in transgenic CMS plants resulted in abnormal function of some genes involved in energy metabolism. When orf165 in transgenic CMS plant was silenced, the resulted orf165-silenced plant was male fertile and the expression patterns of some genes associated with energy metabolism were similar to ML-14B. Thus, we confirmed that orf165 influenced CMS in pepper.

ABSTRACT Climate change and prolong drought adversely affect the grassland ecosystem, is precarious environmental constraint restricting plant growth and productivity. An experiment was conducted to alleviate adverse impacts of drought on physiochemical and morphological attributes of Leymus chinensis (Trin.) Tzvelev using brassinosteroid (BR). Treatments comprised well watered control (soil water contents 80%-85%) including Control (T0) and Control+ BR (TB0), moderate drought stress (soil water contents 50%-55%) including (T1) and T1+ BR (TB1) and severe drought stress (soil water contents 30%-35%) including (T2) and T2+ BR (TB2), they were laid out in completely randomized design with five replicates. Drought stress significantly impaired growth, osmotic substances, photosynthetic rate, and other physiochemical process. Moreover, perturbation in recorded attributes was aggravated by increasing drought severity from moderate to severe. Nevertheless, BR application (0.1 mg L-1) improved plant weight (38.8%-46.2%), relative water content (23.4%-29.1%), chlorophyll a (16.6%-56.5%), chlorophyll b (8.5%-16.9%), carotenoids (29.1%-67.3%), soluble sugars (1.7%-29.4%), free amino acids (15.4%-19.4%), and proline content (45.2%-79.4%); while, lowered malondialdehyde (34.8%-45.4%) at each level of drought. Likewise, BR application enhanced net photosynthetic rate (69.8%-165.1%), transpiration rate (45.0%-146.9%), water utilization efficiency (9.3%-16.0%), carboxylation utilization efficiency (80%- 250%), sunlight utilization efficiency (66.6%-158.8%) and improved chlorophyll fluorescence characteristics at each level of drought, as compared to untreated controls. The adverse implications on physiochemical and morphological attributes were aggravated with the enhancing severity of drought from control to severe drought. Yet, 0.1 mg L-1 exogenous BR improved morphological and physiochemical attributes remarkably over respective controls and hence can be used to improve growth of drought stressed L. chinensis.

RESUMO: A aplicação de herbicidas é um método eficaz de controle de ervas daninhas para mitigar a perda de produtividade das culturas. No entanto, o uso excessivo de herbicidas pode causar toxicidade em plantas não alvo. O presente estudo avaliou os efeitos da dose recomendada para aplicação agrícola (0.45 kg ha-1) e dose excessiva (0.90 kg ha-1) de glufosinato no desempenho fotossintético e assimilação de nitrogênio das variedades de colza D148 e Zhongshuang 11 (ZS11). Ambas as concentrações de glutamato diminuíram significativamente o teor de clorofila e compostos azotados, exceto a prolina livre, e a atividade de síntese da glutamina e de síntese de glutamato, e aumentaram a atividade de desidrogenase do ácido glutâmico em ambas as variedades. Quando a concentração de glifosato foi 0.45 kg ha-1, a assimilação de azoto das duas variedades diminuiu, o que indicou que a dosagem recomendada de glifosato inibiu a assimilação de azoto das duas variedades de colza. Entretanto, a taxa fotosintética líquida do D148 aumentou enquanto o do ZS11 diminuiu, o que significa que o D148 é mais tolerante a dose recomendada de glifosato do que o ZS11. A dose de 0.90 kg ha-1 de glifosato foi prejudicial para as mudas de duas variedades de colza. Em geral, os nossos resultados indicam que o uso excessivo de glufosinato inibe a taxa fotossintética e a assimilação de nitrogênio em mudas de colza, sendo essencial aplicar uma dose adequada deste herbicida com base na variedade cultivada para minimizar os efeitos adversos nas culturas e no meio ambiente.

ABSTRACT: Herbicide application is an effective weed control method for mitigating crop yield loss; however, herbicide overuse can cause toxicity in non-target plants. The present study evaluated the effects of glufosinate at recommended dose for agricultural application (0.45 kg ha-1) and at overuse dose (0.90 kg ha-1) glufosinate application on photosynthetic performance and nitrogen assimilation of the rapeseed varieties D148 and Zhongshuang 11 (ZS11). Both glufosinate concentrations significantly decreased the content of chlorophyll and nitrogenous compounds, except free proline, and the activity of glutamine synthetase and glutamate synthase, and increased the activity of glutamic acid dehydrogenase in both varieties. When the concentration of glyphosate was 0.45kg ha-1, the nitrogen assimilation of the two varieties decreased, which indicated that the recommended dosage inhibited the nitrogen assimilation of the two varieties; however, the increase of net photosynthetic rate of D148 and the decrease of that of ZS11 mean that D148 is more tolerant to the recommended dose of glyphosate than ZS11. The 0.90 kg ha-1 dosage was toxic to both rapeseed varieties. Overall, our results indicated that herbicide overuse inhibited the photosynthetic rate and nitrogen assimilation in rapeseed seedlings, and it is essential to apply a suitable glufosinate dose based on the variety grown to minimize adverse effects on crops and environment.

Abstract The measurement of gene expression can provide important information about gene function and the molecular basis for developmental processes. We analyzed the transcriptomes at three different developmental stages of pepper flower [sporogenous cell division, stage (B1); pollen mother cell meiosis, stage (B2); and open flower (B3)]. In the cDNA libraries for B1, B2, and B3: 82718, 77061, and 91491 unigenes were assembled, respectively. A total of 34,445 unigene sequences and 128 pathways were annotated by KEGG pathway analysis. Several genes associated with nectar biosynthesis and nectary development were identified, and 8,955, 12,182, and 23,667 DEGs were identified in the B2 vs B1, B3 vs B1, and B3 vs. B2 comparisons. DEGs were involved in various metabolic processes, including flower development, nectar biosynthesis, and nectary development. According to the RNA-seq data, all 13 selected DEGs showed similar expression patterns after q-PCR analysis. Sucrose-phosphatase, galactinol-sucrose galactosyltransferase, and sucrose synthase played very important roles in nectar biosynthesis, and CRABS CLAW could potentially be involved in mediating nectary development. A significant number of simple sequence repeat and single nucleotide polymorphism markers were predicted in the Capsicum annuum sequences. The new results provide valuable genetic information about flower development in pepper.

ABSTRACT Different light and shade intensities are the main constraints to achieve potential biomass accumulation in Leymus chinensis (Trin.) Tzvelev. An experiment was conducted to explain the physiochemical and morphological adversity triggered by various light intensities. Adverse impacts were lessened with exogenous brassinolide (BR). Treatments consisted of 100% natural light (T0), 100% natural light + 0.1 mg L-1 BR (BT0), light shade (70% natural light) (T1), light shade + BR (70% natural light + 0.1 mg L-1 BR) (BT1), moderate shade (50% natural light) (T2), and moderate shade + BR (50% natural light + 0.1 mg L-1 BR) (BT2). These were completely randomized design treatments with five replicates. Results showed that dry biomass production and endogenous hormone levels (abscisic acid [ABA], zeatin riboside [ZR], gibberellic acid [GA], and indole acetic acid [IAA]) increased, while osmolyte accumulation (soluble sugars and proteins, free amino acids, and proline), antioxidant activity (peroxidase [POD], superoxide dismutase [SOD], and catalase [CAT]), and lipid peroxidation decreased under shade at T0. Treatment T1 depicted the most promising results for these attributes. However, biomass accumulation (33%-56%), osmotic substances (soluble sugars,13%-38%; soluble proteins, 9%-41%; free amino acids, 8%-16%; proline, 11%-41%), and antioxidant enzyme activities (POD, 11%-14%; SOD, 3%-33%; CAT, 4%-23%) increased. On the other hand, lipid peroxidation was reduced by BR application, as indicated by decreased malondialdehyde (MDA) content (7%-31%) and relative conductivity (7%-19%) under both natural and shade conditions. Likewise, the biosynthesis of ABA (2%-22%), ZR (11%-24%), and GA (30%-50%) improved under exogenous BR compared with the control. The IAA contents (22%-28%) decreased under foliar-applied BR compared with the control. Results suggested that light to moderate shade improved the biomass production and physiological performance of L. chinensis, while BR application exhibited further improvement

Salt stress is one of major problem hampering plant growth and development to a significant level. In present study, 5-aminolevulinic acid (ALA) was exogenously applied to Leymus chinensis (Trin.) Tzvel. plants at various concentrations (10, 50, and 100 mg L-1) to assess its effects on morphology, physiology, and biochemistry under salt stress conditions (150 mmol NaCl L-1) as compared with control. The results indicated that salt stress substantially impaired growth, physiology and biochemistry of L. chinensis plants; nonetheless, ALA application alleviated the adverse effects of salt stress. Application of ALA improved the leaf length, leaf area, leaf conductance, plant dry biomass, water contents, and root activity of L. chinensis under stress and no stress conditions. Additionally, biosynthesis of chlorophyll, carotenoids, free proline, soluble sugars and proteins of L. chinensis plants was also increased following ALA application as compared to control, under salt stress conditions. Moreover, we also observed an enhanced activity of antioxidant defense system in L. chinensis in response to ALA application. ALA elevated the activity of enzymatic antioxidants viz. ascorbate peroxidase (APX), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) significantly scavenged reactive oxygen species thus reduced the accumulation of malondialdehyde (MDA) under salt stress as compared to control under both normal and stressed conditions. The effect of ALA on all growth and biochemical attributes was concentration dependent and application of 50 as well as 100 mg L-1 ALA proved better. The results concluded that salt stress tolerance in L. chinensis plants can be increased by exogenously applied ALA at appropriate concentration. It was suggested that L. chinensis plants were treated with ALA application of 50-100 mg L-1 was more beneficial under both normal and saline conditions.

Plant growth regulating substances are involved in the physiological and metabolic processes of plants and enable them to cope with numerous environmental stresses. The effect of exogenously applied brassinolide (BR) with various concentrations (0.01, 0.1, and 1.0 mg L-1) was studied on morphological and physiological traits of Leymus chinensis (Trin.) Tzvelev under room and high temperatures in pots. The experimental results revealed that high temperature stress substantially perturbed growth, photosynthetic pigments, and root activity of L. chinensis; however, the deleterious effects of high temperature were partially ameliorated by the foliar application of BR. Compared to room temperature, high temperature stress decreased the plant height, leaf area, plant fresh and dry weight, chlorophyll a and b content, chlorophyll a/b ratio as well as root activity, while exacerbated the membrane damage as indicated by enhanced production of malondialdehyde (MDA). Accumulation of proline content, soluble protein and sugar content in L. chinensis improved by heat stress, compared with normal temperature; application of BR further improved their production thus aiding in the attainment of tolerance against heat stress. Elevated levels of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) were observed under heat stress compared to room temperature, however, application of BR further proved beneficial in this regard. Our results indicated that BR could improve the growth and development of L. chinensis by enhancing the biosynthesis of photosynthetic pigments, osmolytes and antioxidant enzymes system in plants under both room and high temperature.

A investigação química das plantas Phyllanthus cochinchinensis (Euphorbiaceae) levou ao isolamento de três novos glicosídeos fenólicos, filantuosídeos A-C, juntamente com 12 compostos conhecidos. Suas estruturas foram determinadas com base em extensivas análises espectroscópicas e métodos químicos. Dentre eles, filantuosídeos A e B são dois glicosídeos fenólicos raros, com um esqueleto C6-C3-C6. A configuração absoluta dos filantuosídeos A e B foi estabelecida por dicroísmo circular elétrico calculado (ECD) usando teoria do funcional da densidade e a sua abordagem dependente do tempo (TDDFT). Os compostos isolados também tiveram sua citotoxicidade e atividade antimicrobial testadas.

Chemical investigation of the whole plants of Phyllanthus cochinchinensis (Euphorbiaceae) led to the isolation of three new phenolic glycosides, phyllanthuosides A-C, together with 12 known compounds. Their structures were established on the basis of extensive spectroscopic analysis and chemical methods. Among them, phyllanthuosides A and B are two of the rare phenolic glycosides, featuring with a C6-C3-C6 skeleton. The absolute configurations of phyllanthuosides A and B were established by calculated electric circular dichroism (ECD) using time dependent density functional theory (TDDFT). The isolates were also tested for their cytotoxicity and antimicrobial activity.