The LEA gene family in tomato and its wild relatives: genome-wide identification, structural characterization, expression profiling, and role of SlLEA6 in drought stress.

BACKGROUND: Late embryogenesis abundant (LEA) proteins are widely distributed in higher plants and play crucial roles in regulating plant growth and development processes and resisting abiotic stress. Cultivated tomato (Solanum lycopersicum) is an important vegetable crop worldwide; however, its growth, development, yield, and quality are currently severely constrained by abiotic stressors. In contrast, wild tomato species are more tolerant to abiotic stress and can grow normally in extreme environments. The main objective of this study was to identify, characterize, and perform gene expression analysis of LEA protein families from cultivated and wild tomato species to mine candidate genes and determine their potential role in abiotic stress tolerance in tomatoes. RESULTS: Total 60, 69, 65, and 60 LEA genes were identified in S. lycopersicum, Solanum pimpinellifolium, Solanum pennellii, and Solanum lycopersicoides, respectively. Characterization results showed that these genes could be divided into eight clusters, with the LEA_2 cluster having the most members. Most LEA genes had few introns and were non-randomly distributed on chromosomes; the promoter regions contained numerous cis-acting regulatory elements related to abiotic stress tolerance and phytohormone responses. Evolutionary analysis showed that LEA genes were highly conserved and that the segmental duplication event played an important role in evolution of the LEA gene family. Transcription and expression pattern analyses revealed different regulatory patterns of LEA genes between cultivated and wild tomato species under normal conditions. Certain S. lycopersicum LEA (SlLEA) genes showed similar expression patterns and played specific roles under different abiotic stress and phytohormone treatments. Gene ontology and protein interaction analyses showed that most LEA genes acted in response to abiotic stimuli and water deficit. Five SlLEA proteins were found to interact with 11 S. lycopersicum WRKY proteins involved in development or resistance to stress. Virus-induced gene silencing of SlLEA6 affected the antioxidant and reactive oxygen species defense systems, increased the degree of cellular damage, and reduced drought resistance in S. lycopersicum. CONCLUSION: These findings provide comprehensive information on LEA proteins in cultivated and wild tomato species and their possible functions under different abiotic and phytohormone stresses. The study systematically broadens our current understanding of LEA proteins and candidate genes and provides a theoretical basis for future functional studies aimed at improving stress resistance in tomato.

[Cloning and prokaryotic expression of FcLEA-D29 gene of Fritillaria cirrhosa].

Fritillaria cirrhosa, the most valuable source of the precious Chinese medicinal material Fritillariae Cirrhosae Bulbus, suffers from various stresses during growth which influence the yield and quality of the medicinal part. This study aims to explore the genes related to stress resistance in this medicinal species. To be specific, based on the transcriptome data of F. cirrhosa, a gene encoding the late embryogenesis abundant(LEA) protein was obtained, which was named as FcLEA-D29. The gene sequence and protein structure were analyzed with bioinformatics methods and qRT-PCR was used to detect the expression of the gene in different tissues and in response to temperature stress. The low-temperature tolerance of FcLEA-D29 was verified by the prokaryotic expression system. The results showed that FcLEA-D29 contained an open reading frame of 777 bp, encoding 258 amino acids. Multiple sequence alignment revealed that FcLEA-D29 protein belonged to LEA-D29 subfamily of LEA3 family. qRT-PCR results showed that FcLEA-D29 was specifically expressed in bulbs and responded to low temperature. The strain with the recombinant plasmid demonstrated better growth status than the control strain in the instance of low temperature stress, suggesting that FcLEA-D29 may play a role in bulb development and low temperature response of F. cirrhosa. This study laid a basis for further research on the role of FcLEA-D29 in the accumulation of secondary metabolites in F. cirrhosa, especially alkaloids, under low temperature and provided evidence for the low-temperature adaptation of F. cirrhosa.

Transcriptomic and metabolomic profiling of Camellia sinensis L. cv. 'Suchazao' exposed to temperature stresses reveals modification in protein synthesis and photosynthetic and anthocyanin biosynthetic pathways.

To determine the mechanisms in tea plants responding to temperature stresses (heat and cold), we examined the global transcriptomic and metabolomic profiles of the tea plant cultivar 'Suchazao' under moderately low temperature stress (ML), severely low temperature stress (SL), moderately high temperature stress (MH) and severely high temperature stress (SH) using RNA-seq and high performance liquid chromatography tandem mass spectrometry/mass spectrometry (HPLC-MS/MS), respectively. The identified differentially expressed genes indicated that the synthesis of stress-resistance protein might be redirected to cope with the temperature stresses. We found that heat shock protein genes Hsp90 and Hsp70 played more critical roles in tea plants in adapting to thermal stress than cold, while late embryogenesis abundant protein genes (LEA) played a greater role under cold than heat stress, more types of zinc finger genes were induced under cold stress as well. In addition, energy metabolisms were inhibited by SH, SL and ML. Furthermore, the mechanisms of anthocyanin synthesis were different under the cold and heat stresses. Indeed, the CsUGT75C1 gene, encoding UDP-glucose:anthocyanin 5-O-glucosyl transferase, was up-regulated in the SL-treated leaves but down-regulated in SH. Metabolomics analysis also showed that anthocyanin monomer levels increased under SL. These results indicate that the tea plants share certain foundational mechanisms to adjust to both cold and heat stresses. They also developed some specific mechanisms for surviving the cold or heat stresses. Our study provides effective information about the different mechanisms tea plants employ in surviving cold and heat stresses, as well as the different mechanisms of anthocyanin synthesis, which could speed up the genetic breeding of heat- and cold-tolerant tea varieties.

The late embryogenesis abundant gene family in tea plant (Camellia sinensis): Genome-wide characterization and expression analysis in response to cold and dehydration stress.

Late embryogenesis abundant (LEA) proteins are a large and highly diverse family of polypeptides that play important roles in plant growth, development and stress responses. At present, LEA gene families have been identified and systematically characterized in many plant species. However, the LEA gene family in tea plant has not been revealed, and the biological functions of the members of this family remain unknown. In this study, 33 CsLEA genes were identified from tea plant via a genome-wide study, and they were clustered into seven groups according to analyses of their phylogenetic relationships, gene structures and protein conserved motifs. In addition, expression analysis revealed that the CsLEA genes were specifically expressed in one or more tissues and significantly induced under cold and dehydration stresses, implying that CsLEA genes play important roles in tea plant growth, development and response to cold and dehydration stresses. Furthermore, a potential transcriptional regulatory network, including DREB/CBF, MYB, bZIP, bHLH, BPC and other transcription factors, is directly associated with the expression of CsLEA genes, which may be ubiquitous and important in the above mentioned processes. This study could help to increase our understanding of CsLEA proteins and their contributions to stress tolerance in tea plant.

The Colour Treatment: A Convergence of Art and Medicine at the Red Cross Russell Lea Nerve Home.

When the Red Cross opened its new convalescent home at Russell Lea in Sydney in 1919, it contained a coloured room designed for treating 'nerve cases'. This room was painted by Roy de Maistre, a young artist, and was modelled on the Kemp Prossor colour scheme trialled at the McCaul Convalescent Hospital in London for the treatment of shell shock. Dubbed the 'colour cure' by the popular press, this unconventional treatment was ignored by the Australian medical profession. The story of de Maistre's colour experiment is not widely known outside the specialist field of Australian art history. Focusing on the colour room as a point of convergence between art and medicine in the context of the First World War, this article investigates Red Cross activities and the care of soldiers suffering from nervous conditions.

Metabolomics uncovers dietary omega-3 fatty acid-derived metabolites implicated in anti-nociceptive responses after experimental spinal cord injury.

Chronic neuropathic pain is a frequent comorbidity following spinal cord injury (SCI) and often fails to respond to conventional pain management strategies. Preventive administration of docosahexaenoic acid (DHA) or the consumption of a diet rich in omega-3 polyunsaturated fatty acids (O3PUFAs) confers potent prophylaxis against SCI and improves functional recovery. The present study examines whether this novel dietary strategy provides significant antinociceptive benefits in rats experiencing SCI-induced pain. Rats were fed control chow or chow enriched with O3PUFAs for 8weeks before being subjected to sham or cord contusion surgeries, continuing the same diets after surgery for another 8 more weeks. The paw sensitivity to noxious heat was quantified for at least 8weeks post-SCI using the Hargreaves test. We found that SCI rats consuming the preventive O3PUFA-enriched diet exhibited a significant reduction in thermal hyperalgesia compared to those consuming the normal diet. Functional neurometabolomic profiling revealed a distinctive deregulation in the metabolism of endocannabinoids (eCB) and related N-acyl ethanolamines (NAEs) at 8weeks post-SCI. We found that O3PUFAs consumption led to a robust accumulation of novel NAE precursors, including the glycerophospho-containing docosahexaenoyl ethanolamine (DHEA), docosapentaenoyl ethanolamine (DPEA), and eicosapentaenoyl ethanolamine (EPEA). The tissue levels of these metabolites were significantly correlated with the antihyperalgesic phenotype. In addition, rats consuming the O3PUFA-rich diet showed reduced sprouting of nociceptive fibers containing CGRP and dorsal horn neuron p38 mitogen-activated protein kinase (MAPK) expression, well-established biomarkers of pain. The spinal cord levels of inositols were positively correlated with thermal hyperalgesia, supporting their role as biomarkers of chronic neuropathic pain. Notably, the O3PUFA-rich dietary intervention reduced the levels of these metabolites. Collectively, these results demonstrate the prophylactic value of dietary O3PUFA against SCI-mediated chronic pain.