Alfalfa is the most extensively cultivated forage legume. Salinity is a major environmental factor that impacts on alfalfa’s productivity. However, little is known about the molecular mechanisms underlying alfalfa responses to salinity, especially the relative contribution of the two important components of osmotic and ionic stress. In this study, we constructed the first full-length transcriptome database for alfalfa root tips under continuous NaCl and mannitol treatments for 1, 3, 6, 12, and 24 h (three biological replicates for each time points, including the control group) via PacBio Iso-Seq. This resulted in the identification of 52,787 full-length transcripts, with an average length of 2551 bp. Global transcriptional changes in the same 33 stressed samples were then analyzed via BGISEQ-500 RNA-Seq. Totals of 8861 NaCl-regulated and 8016 mannitol-regulated differentially expressed genes (DEGs) were identified. Metabolic analyses revealed that these DEGs overlapped or diverged in the cascades of molecular networks involved in signal perception, signal transduction, transcriptional regulation, and antioxidative defense. Notably, several well characterized signalling pathways, such as CDPK, MAPK, CIPK, and PYL-PP2C-SnRK2, were shown to be involved in osmotic stress, while the SOS core pathway was activated by ionic stress. Moreover, the physiological shifts of catalase and peroxidase activity, glutathione and proline content were in accordance with dynamic transcript profiles of the relevant genes, indicating that antioxidative defense system plays critical roles in response to salinity stress. Overall, our study provides evidence that the response to salinity stress in alfalfa includes both osmotic and ionic components. The key osmotic and ionic stress-related genes are candidates for future studies as potential targets to improve resistance to salinity stress via genetic engineering.

Cultivated alfalfa (Medicago sativa L.) is one of the most important perennial legume forages in the world, and it has considerable potential as a valuable forage crop for livestock. However, the molecular mechanisms underlying alfalfa responses to cold stress are largely unknown. In this study, the transcriptome changes in alfalfa under cold stress at 4 °C for 2, 6, 24, and 48 h (three replicates for each time point) were analyzed using the high-throughput sequencing platform, BGISEQ-500, resulting in the identification of 50,809 annotated unigenes and 5283 differentially expressed genes (DEGs). Metabolic pathway enrichment analysis demonstrated that the DEGs were involved in carbohydrate metabolism, photosynthesis, plant hormone signal transduction, and the biosynthesis of amino acids. Moreover, the physiological changes of glutathione and proline content, catalase, and peroxidase activity were in accordance with dynamic transcript profiles of the relevant genes. Additionally, some transcription factors might play important roles in the alfalfa response to cold stress, as determined by the expression pattern of the related genes during 48 h of cold stress treatment. These findings provide valuable information for identifying and characterizing important components in the cold signaling network in alfalfa and enhancing the understanding of the molecular mechanisms underlying alfalfa responses to cold stress.

Alfalfa is the most extensively cultivated forage legume worldwide. However, the molecular mechanisms underlying alfalfa responses to exogenous abscisic acid (ABA) are still unknown. In this study, the first global transcriptome profiles of alfalfa roots under ABA treatments for 1, 3 and 12 h (three biological replicates for each time point, including the control group) were constructed using a BGISEQ-500 sequencing platform. A total of 50,742 isoforms with a mean length of 2541 bp were generated, and 4944 differentially expressed isoforms (DEIs) were identified after ABA deposition. Metabolic analyses revealed that these DEIs were involved in plant hormone signal transduction, transcriptional regulation, antioxidative defense and pathogen immunity. Notably, several well characterized hormone signaling pathways, for example, the core ABA signaling pathway, was activated, while salicylic acid, jasmonate and ethylene signaling pathways were mainly suppressed by exogenous ABA. Moreover, the physiological work showed that catalase and peroxidase activity and glutathione and proline content were increased after ABA deposition, which is in accordance with the dynamic transcript profiles of the relevant genes in antioxidative defense system. These results indicate that ABA has the potential to improve abiotic stress tolerance, but that it may negatively regulate pathogen resistance in alfalfa.

Dodder species (Cuscuta spp.) are holoparasites that have extensive material exchange with their host plants through vascular connections. Recent studies on cross-species transfer have provided breakthrough insights, but little is known about the interaction mechanisms of the inter-plant mobile substances in parasitic systems. We sequenced the transcriptomes of dodder growing on soybean hosts to characterize the long non-coding RNA (lncRNA) transfer between the two species, and found that lncRNAs can move in high numbers (365 dodder lncRNAs and 14 soybean lncRNAs) in a bidirectional manner. Reverse transcription-polymerase chain reaction further confirmed that individual lncRNAs were trafficked in the dodder–soybean parasitic system. To reveal the potential functions of mobile transcripts, the Gene Ontology terms of mobile lncRNA target genes were predicted, and mobile dodder target genes were found to be mainly enriched in “metabolic process”, “catalytic activity”, “signaling”, and “response to stimulus” categories, whereas mobile soybean target genes were enriched in organelle-related categories, indicating that specific mobile lncRNAs may be important in regulating dodder parasitism. Our findings reveal that lncRNAs are transferred between dodder and its host soybean plants, which may act as critical regulators to coordinate the host–dodder interaction at the whole parasitic level.

This study was undertaken to identify oat (Avena sativa L.) varieties optimal for cultivation in the Jiuquan region, China, in 2021. A selection of 27 domestic and international oat varieties were analyzed, considering ten key agronomic traits, including plant height, stem diameter, spike length, leaf width, and yield. Employing methods such as cluster analysis, principal component analysis, and grey correlation degree, a comprehensive evaluation was conducted. The principal component analysis distilled the ten indicators to three core components. The most influential factors in the first principal component were plant height, ear length, and hay yield, while leaf length and leaf area index were the highest contributors to the second component. The stem-to-leaf ratio emerged as the principal indicator in the third component. The cluster analysis resulted in the classification of the 27 oat varieties into 3 categories. Following a comprehensive evaluation through the grey correlation degree and principal component analysis methodologies, we found that the oat varieties Sweety 1, Fuyan 1, Dingyan 2, Baler, Quebec, and Longyan 2 received the highest scores. These varieties, hence, appear to be the most suitable for cultivation and promotion in the Jiuquan region. This study thus provides invaluable insights into oat cultivation practices, offering guidance for farmers, agricultural policymakers, and future research in the field.

The practice of intercropping in Rosa roxburghii Tratt orchards holds potential for enhancing fruit yield and financial benefits, yet remains insufficiently explored. To address this, we delved into the effects of intercropping on fruit yield and financial viability of R. roxburghii orchards in Longli County, southern China. Orchards of varying ages (4 years old and 5 years old; 7 years old and 8 years old) were subjected to different treatments: (i) Zea mays and Capsicum annuum intercropping, and clean tillage for younger orchards, and (ii) Lolium perenne, natural grass, and clean tillage for older orchards. Each treatment was assessed for its impact on fruit yield and financial benefits. In younger orchards, intercropping with Z. mays and C. annuum did not significantly elevate fruit yield compared to clean tillage in the 4-year-old orchard; however, C. annuum intercropping significantly improved fruit yield in the 5-year-old orchard. Concurrently, intercropping significantly augmented the total financial benefit by 9234.35–10,486.25 CNY ha⁻¹ (Z. mays) and 14,304.90–16,629.18 CNY ha⁻¹ (C. annuum) compared to clean tillage. In older orchards, L. perenne intercropping significantly elevated fruit yield by 598.84–803.64 kg·ha⁻¹, while natural grass reduced it by 394.61–986.24 kg·ha⁻¹, compared to clean tillage. Additionally, L. perenne intercropping significantly boosted the total financial benefit by 8873.92–9956.56 CNY ha⁻¹, whereas natural grass negatively impacted financial benefits by 78.42–2444.94 CNY ha⁻¹ compared to clean tillage. Collectively, our results illustrate that judicious selection of intercrops, based on orchard age and conditions, can significantly enhance both fruit yield and financial advantages in R. roxburghii orchards. This study furnishes vital insights for orchard management and accentuates the prospective merits of intercropping in fruit production systems.