Multi-omic dissection of the cold resistance traits of white water lily.

The white water lily (Nymphaea candida), exemplifying nature's resilience, thrives in the high-altitude terrains of Xinjiang, China, serving as an ideal model for investigating cold adaptation mechanisms in aquatic plants. This study meticulously elucidates the complex cold adaptation mechanisms of the white water lily through a comprehensive and integrated methodological approach. We discovered that the water lily undergoes ecodormancy in winter, retaining high cellular viability and growth potential. During overwintering, the white water lily demonstrates effective resource reallocation, a process facilitated by morphological adjustments, thereby strengthening its resistance to cold temperatures. This enhancement is achieved particularly through the compartmentalization of large vacuoles, the accumulation of osmoregulatory substances, and an increased antioxidant capacity. We established the first exhaustive full-length transcriptome for the white water lily. A subsequent comprehensive analysis of the transcriptome, phytohormones, and metabolome uncovered a multifaceted regulatory network orchestrating cold adaptation. Our research spotlights phytohormone signaling, amino acid metabolism, and circadian rhythms as key elements in the water lily's defense against cold. The results emphasize the critical role of nitrogen metabolism, especially amino acid-related pathways, during cold stress. Metabolite profiling revealed the importance of compounds like myo-inositol and L-proline in enhancing cold tolerance. Remarkably, our study demonstrates that the white water lily notably diminishes the utilization of unsaturated fatty acids in its temperature regulation strategies. In conclusion, this research substantially enriches our understanding of the white water lily's intricate cold adaptation mechanisms, offering new perspectives on the adaptive strategies of aquatic plants and potential applications in agricultural advancement.

Construction of a Membrane Yeast Two-Hybrid Library and Screening of MsPYR1-Like Interacting Proteins in Malus sieversii.

To investigate the biological effects of the ABA receptor pyrabactin resistance 1-like (PYR1-like) in Malus sieversii seeds, the proteins interacting with MsPYR1-like were screened by the membrane yeast two-hybrid library based on the split-ubiquitin system, and to construct the bait vector pBT3-SUC-PYR1 for Malus sieversii cDNA library, which had no self-activating effect on the yeast cells of the pPR3-N membrane yeast two-hybrid library. The library titer assay showed that it could meet the requirements for membrane yeast two-hybrid library screening. After sequencing, GenBank database blast, and yeast rotary validation, 28 candidate proteins interacting with MsPYR1-like were obtained, including ribosomal proteins, late embryogenesis abundant proteins, F-actin-capping proteins, phytochrome-interacting proteins, low-temperature-inducible 65 kDa protein-like, senescence-associated, PP2C and SnRK2 family members, and unknown proteins. Gene ontology analysis of the interaction proteins was related to plant hormone response and negative regulation of seed germination, overexpression of MsPYR1-like in Arabidopsis negatively regulates seed germination, and the study of the biological roles of MsPYR1-like interacting proteins lays the foundation for revealing the lifting of seed dormancy in Malus sieversii.

Comparative transcriptome analysis reveals the regulatory mechanisms of two tropical water lilies in response to cold stress.

BACKGROUND: Tropical water lily is an aquatic plant with high ornamental value, but it cannot overwinter naturally at high latitudes. The temperature drop has become a key factor restricting the development and promotion of the industry. RESULTS: The responses of Nymphaea lotus and Nymphaea rubra to cold stress were analyzed from the perspective of physiology and transcriptomics. Under the cold stress, Nymphaea rubra had obvious leaf edge curling and chlorosis. The degree of peroxidation of its membrane was higher than that of Nymphaea lotus, and the content of photosynthetic pigments also decreased more than that of Nymphaea lotus. The soluble sugar content, SOD enzyme activity and CAT enzyme activity of Nymphaea lotus were higher than those of Nymphaea rubra. This indicated that there were significant differences in the cold sensitivity of the two varieties. GO enrichment and KEGG pathway analysis showed that many stress response genes and pathways were affected and enriched to varying degrees under the cold stress, especially plant hormone signal transduction, metabolic pathways and some transcription factor genes were from ZAT gene family or WKRY gene family. The key transcription factor ZAT12 protein in the cold stress response process has a C2H2 conserved domain, and the protein is localized in the nucleus. Under the cold stress, overexpression of the NlZAT12 gene in Arabidopsis thaliana increased the expression of some cold-responsive protein genes. The content of reactive oxygen species and MDA in transgenic Arabidopsis thaliana was lower, and the content of soluble sugar was higher, indicating that overexpression of NlZAT12 can improve the cold tolerance of Arabidopsis thaliana. CONCLUSION: We demonstrate that ethylene signalling and reactive oxygen species signalling play critical roles in the response of the two cultivars to cold stress. The key gene NlZAT12 for improving cold tolerance was identified. Our study provides a theoretical basis for revealing the molecular mechanism of tropical water lily in response to cold stress.

Comparative transcriptome analysis of melon (Cucumis melo L.) reveals candidate genes and pathways involved in powdery mildew resistance.

Powdery mildew is a major disease in melon, primarily caused by Podosphaera xanthii (Px). Some melon varieties were resistant to powdery mildew, while others were susceptible. However, the candidate genes associated with resistance and the mechanism of resistance/susceptibility to powdery mildew in melon remain unclear. In this study, disease-resistant melon cultivar TG-1 and disease-susceptible melon cultivar TG-5 were selected for comparative transcriptome analysis. The results suggested that the numbers of differentially expressed genes (DEGs) in TG-5 was always more than that in TG-1 at each of the four time points after Px infection, indicating that their responses to Px infection may be different and that the active response of TG-5 to Px infection may be earlier than that of TG-1. Transcription factors (TFs) analysis among the DEGs revealed that the bHLH, ERF, and MYB families in TG-1 may play a vital role in the interaction between melon and powdery mildew pathogens. GO enrichment analysis of these DEGs in TG-5 showed that the SBP, HSF, and ERF gene families may play important roles in the early stage of melon development after Px infection. Finally, we speculated on the regulatory pathways of melon powdery mildew and found PTI and ABA signaling genes may be associated with the response to Px infection in melon.

The short-term pulsatile ventricular assist device for postcardiotomy cardiogenic shock: a clinical trial in China.

Despite the recent advances in myocardial protection, surgical techniques, intra-aortic balloon therapy, and maximal pharmacological support, postoperative ventricular dysfunction continues to occur in 0.5-1.0% of all patients undergoing cardiac surgery. Ventricular assist device (VAD) is an important therapeutic adjunct in treating patients with profound ventricular dysfunction with postcardiotomy cardiogenic shock. The purpose of this report was to describe the clinical results with the China-made Luo-Ye VAD as a short-term circulatory support. From May 1998 to December 2006, 17 patients with postcardiotomy cardiogenic shock were supported by the Luo-Ye VAD. Of these patients, 10 were males and seven were females with a mean age of 49.6 years (range 36-68 years). All cases were supported by left VAD (LVAD). Mean duration of support was 46.3 h (range 13-113 h). A criteria of insertion was established to standardize implantation criteria. Among the 17 patients treated with LVAD, eight (47.1%) patients were weaned from support and seven (41.2%) patients were discharged from hospital. Ten (58.8%) patients died while on LVAD support (nine cases) or shortly after weaning (one case). The causes of death in the entire group were cardiac (40%), renal failure (20%), neurologic (10%), sepsis (10%), and multiple organ system failure (20%). The complications were represented by bleeding, renal failure, neurologic event, infection, ventricular arrhythmias, etc. The Luo-Ye VAD functioned well and proved to be useful in patients with postcardiotomy cardiogenic shock. It carries a less-postoperative anticoagulant and a low incidence of VAD-related complications. The survival rate was encouraging in our small cohort of patients.

Study on mechanical circulatory support and currently available supporting parts in China.

The research and development on extracorporeal and assisted circulation in China have been painstaking. On one hand, China has the largest population of 1.3 [corrected] billion in the world, and the demands for supporting equipment are huge. On the other hand, as a developing country, China is not wealthy. It is urgent to design and fabricate affordable circulatory support parts, machines, and artificial hearts for Chinese market. In this regard, we have made our own heart-lung machine, mechanical and tissue valves, oxygenators, and artificial hearts and their improved versions. The cost of these parts is much lower as compared with those in the Western market. Although the results of clinical application are good so far, the quality of these lifesaving parts needs to be continuously improved.