TMT-Based Quantitative Proteomic Analysis Reveals the Physiological Regulatory Networks of Embryo Dehydration Protection in Lotus (Nelumbo nucifera)

Proteomic Profiling of Cocos nucifera L. Zygotic Embryos during Maturation of Dwarf and Tall Cultivars: The Dynamics of Carbohydrate and Fatty Acid Metabolism

There is a limited number of studies analyzing the molecular and biochemical processes regulating the metabolism of the maturation of Cocos nucifera L. zygotic embryos. Our research focused on the regulation of carbohydrate and lipid metabolic pathways occurring at three developmental stages of embryos from the Mexican Pacific tall (MPT) and the Yucatan green dwarf (YGD) cultivars. We used the TMT-synchronous precursor selection (SPS)-MS3 strategy to analyze the dynamics of proteomes from both embryos; 1044 and 540 proteins were determined for the MPT and YGD, respectively. A comparison of the differentially accumulated proteins (DAPs) revealed that the biological processes (BP) enriched in the MPT embryo included the glyoxylate and dicarboxylate metabolism along with fatty acid degradation, while in YGD, the nitrogen metabolism and pentose phosphate pathway were the most enriched BPs. Findings suggest that the MPT embryos use fatty acids to sustain a higher glycolytic/gluconeogenic metabolism than the YGD embryos. Moreover, the YGD proteome was enriched with proteins associated with biotic or abiotic stresses, e.g., peroxidase and catalase. The goal of this study was to highlight the differences in the regulation of carbohydrate and lipid metabolic pathways during the maturation of coconut YGD and MPT zygotic embryos.

An Updated Review on Nelumbo Nucifera Gaertn: Chemical Composition, Nutritional Value and Pharmacological Activities

Nelumbo nucifera Gaertn is a recognised herbal plant in ancient medical sciences. Each portion of the plant leaf, flower, seed and rhizome is utilised for nutritional and medicinal purposes. The chemical compositions like phenol, alkaloids, glycoside, terpenoids and steroids have been isolated. The plant contains various nutritional values like lipids, proteins, amino acids, minerals, carbohydrates, and fatty acids. Traditional medicine confirms that the phytochemicals of plants give significant benefits to the treatment of various diseases such as leukoderma, smallpox, dysentery, haematemesis, coughing, haemorrhage, metrorrhagia, haematuria, fever, hyperlipidaemia, cholera, hepatopathy and hyperdipsia. To verify the traditional claims, researchers have conducted scientific biological in vivo and in vitro screenings, which have exhibited that the plant keeps various notable pharmacological activities such as anticancer, hepatoprotective, antioxidant, antiviral, hypolipidemic, anti-obesity, antipyretic, hypoglycaemic, antifungal, anti-inflammatory and antibacterial activities. This review, summaries the nutritional composition, chemical constituents and biological activities substantiated by the researchers done in vivo and in vitro.

An alfalfa MYB-like transcriptional factor MsMYBH positively regulates alfalfa seedling drought resistance and undergoes MsWAV3-mediated degradation

Drought is a major threat to alfalfa (Medicago sativa L.) production. The discovery of important alfalfa genes regulating drought response will facilitate breeding for drought-resistant alfalfa cultivars. Here, we report a genome-wide association study of drought resistance in alfalfa. We identified and functionally characterized an MYB-like transcription factor gene (MsMYBH), which increases the drought resistance in alfalfa. Compared with the wild-types, the biomass and forage quality were enhanced in MsMYBH overexpressed plants. Combined RNA-seq, proteomics and chromatin immunoprecipitation analysis showed that MsMYBH can directly bind to the promoters of MsMCP1, MsMCP2, MsPRX1A and MsCARCAB to improve their expression. The outcomes of such interactions include better water balance, high photosynthetic efficiency and scavenge excess H2O2 in response to drought. Furthermore, an E3 ubiquitin ligase (MsWAV3) was found to induce MsMYBH degradation under long-term drought, via the 26S proteasome pathway. Furthermore, variable-number tandem repeats in MsMYBH promoter were characterized among a collection of germplasms, and the variation is associated with promoter activity. Collectively, our findings shed light on the functions of MsMYBH and provide a pivotal gene that could be leveraged for breeding drought-resistant alfalfa. This discovery also offers new insights into the mechanisms of drought resistance in alfalfa.

Evaluation of the Susceptibility of Lotus Seeds (Nelumbo nucifera Gaertn.) to Aspergillus flavus Infection and Aflatoxin Contamination

The seeds of lotus (Nelumbo nucifera Gaertn.) have been used as significant medicinal and nutritional ingredients worldwide. The abundant proteins and polysaccharides in lotus seeds make them susceptible to contamination by aflatoxin (AF), a fungal toxic metabolite. This study was conducted to investigate the susceptibility of lotus seeds at different stages of ripening to AF contamination, as well as the mechanism of the contamination. Seven groups of lotus receptacles with seeds at different ripening stages (A-G, from immature to mature) were used for the experiment. Spores of Aspergillus flavus, an AF producer, were inoculated on the water-gap area of the seeds in each receptacle. Then, each receptacle was covered with a sterilized bag, and its stalk part was soaked in water containing a life-prolonging agent, after which it was kept at room temperature for 14 days. The AF content of each whole inoculated seed from the A-G groups and that of each seed part (pericarp, cotyledon, and embryo) from the D and E groups were determined using high-performance liquid chromatography. Microtome sections were prepared from the samples and observed under a light microscope and scanning electron microscope. The seeds from the A and D groups had higher AF contents than the seeds from the B, C, E, F, and G groups, indicating that the condition of the water-gap area and the development of the embryo and cotyledon parts of the seeds are associated with AF contamination.

Genome-wide study and functional characterization elucidates the potential association of late embryogenesis abundant (LEA) genes with lotus seed development

Late embryogenesis abundant (LEA) proteins are extremely hydrophilic proteins imperatively associated with plant growth and development, as well as cell protection from abiotic stress. However, the genome-wide characterization of LEA gene family remains limited, especially in aquatic species such as lotus (Nelumbo spp.). Here, 57 putative LEA genes, including 28 NnLEAs and 29 NlLEAs were identified in the N.nucifera and N.lutea genomes, respectively. A total of 27 homologous LEA gene pairs were identified, indicating high degree of sequence homologies between the two Nelumbo species. Secondary structure prediction indicated high prevalence of alpha (α) helix structure among LEA proteins in the LEA_1, LEA_4, and SMP groups. Screening of putative promoter cis-elements revealed that NnLEA genes were involved in diverse biological processes. Most NnLEA genes were predominantly expressed in the late cotyledons and plumules development stages, suggesting their potential vital roles in lotus seed maturation. In addition, genes co-expressed with NnLEAs were involved in ABA signaling, seed maturation, and development processes. Overall, this study provides new insights for the in-depth understanding of the functions of NnLEA proteins in lotus seed development, and could act as a useful reference for the molecular breeding of seeds with prolonged lifespan.