Meta-analysis of the effect of expression of MYB transcription factor genes on abiotic stress

Meta-analysis of SnRK2 gene overexpression in response to drought and salt stress

SNF1-RELATED KINASE 2 (SnRK2) plays a crucial role in plants' stress response. Although studies have reported that the overexpression of several SnRK2 family members in different plants leads to improved stress tolerance, it is difficult to elucidate the mechanisms by which SnRK2s regulate stress tolerance due to the variability of experimental variables in these studies. Therefore, we used meta-analysis to comprehensively analyze 22 parameters that can reflect drought tolerance and salinity tolerance in SnRK2s-transformed plants and to explore the effects that different experimental variables between studies have on the relevant plant parameters. The results showed that the overexpression of SnRK2s mainly improved plants' drought and salinity tolerance by reducing their osmotic stress and oxidative damage, improving photosynthesis and other biochemical and physiological processes. Out of the 22 physiological parameters, 17 and 19 were significantly affected by drought and salt stress, respectively, and 10 indicators were also significantly changed under non-stress conditions. Under salt stress, the cell membrane permeability among these parameters shows the most significant changes, increasing by 506.57% in SnRK2-overexpressing plants compared to wild type (WT). Therefore, although plants overexpressing SnRK2s respond positively to both drought and salt stress, they demonstrated greater tolerance to salt stress. In addition, among the detected regulatory variables, donor-acceptor type, promoter type, stress type, experimental medium, and duration all affected the extent of SnRK2s overexpression and affected the physiological characteristics of the transgenic plants. Also, different stress conditions (salt, drought stress) led to different degrees of transformation. These studies provide new research directions for studying crop stress tolerance and help to better explore the functions played by SnRK2s in external plant stresses.

Meta-Analysis of the Impact of Far-Red Light on Vegetable Crop Growth and Quality

Far-red lights (FRs), with a wavelength range between 700 and 800 nm, have substantial impacts on plant growth, especially horticultural crops. Previous studies showed conflicting results on the effects of FRs on vegetable growth and quality. Therefore, we conducted a meta-analysis on the influence of FRs on vegetable growth, aiming to provide a comprehensive overview of their effects on the growth and nutritional indicators of vegetables. A total of 207 independent studies from 55 literature sources were analyzed. The results showed that FR treatment had significant effects on most growth indicators, including increasing the fresh weight (+25.27%), dry weight (+21.99%), plant height (+81.87%), stem diameter (+12.91%), leaf area (+18.57%), as well as reducing the content of chlorophyll (-11.88%) and soluble protein (-11.66%), while increasing soluble sugar content (+19.12%). Further subgroup analysis based on various factors revealed significant differences in the effects of FR on different physiological indicators, such as FR intensity, plant species, duration of FR exposure, and the ratio of red light to FR. In general, moderate FR treatment is beneficial for vegetable growth. This study provides important references and guidelines for optimizing the application of FR in the future.

Proline Metabolism Genes in Transgenic Plants: Meta-Analysis under Drought and Salt Stress

The amino acid proline accumulates in plants during abiotic stresses such as drought and salinity and is considered a reliable marker of environmental stress. While its accumulation is well established, its precise role in stress tolerance and its underlying molecular mechanism remain less clear. To address these issues, we performed a meta-analysis-a robust statistical technique that synthesizes results from multiple independent studies while accounting for experimental differences. We focused on 16 physiological and morphological parameters affected by drought and salt stress in transgenic plants expressing proline metabolic genes. For each parameter, we calculated the effect size as the response ratio (RR), which represents the logarithm of the mean value in the transgenic group over the mean value of the control group (lnRR). Under stress, most parameters exhibited significantly higher response ratios in the transgenic group, confirming the beneficial effects of proline during drought and salt stress. Surprisingly, under non-stressed conditions, most stress markers showed no significant differences between transgenic and non-transgenic plants, despite elevated proline levels in the former. These results suggest that the benefits of proline may be related to proline catabolism or may only become apparent during stress, possibly due to interactions with reactive oxygen species (ROS), which accumulate predominantly under stress conditions.

Physiology and Molecular Breeding in Sustaining Wheat Grain Setting and Quality under Spring Cold Stress

Spring cold stress (SCS) compromises the reproductive growth of wheat, being a major constraint in achieving high grain yield and quality in winter wheat. To sustain wheat productivity in SCS conditions, breeding cultivars conferring cold tolerance is key. In this review, we examine how grain setting and quality traits are affected by SCS, which may occur at the pre-anthesis stage. We have investigated the physiological and molecular mechanisms involved in floret and spikelet SCS tolerance. It includes the protective enzymes scavenging reactive oxygen species (ROS), hormonal adjustment, and carbohydrate metabolism. Lastly, we explored quantitative trait loci (QTLs) that regulate SCS for identifying candidate genes for breeding. The existing cultivars for SCS tolerance were primarily bred on agronomic and morphophysiological traits and lacked in molecular investigations. Therefore, breeding novel wheat cultivars based on QTLs and associated genes underlying the fundamental resistance mechanism is urgently needed to sustain grain setting and quality under SCS.

Transcriptome sequencing and differential expression analysis of natural and BTH-treated wound healing in potato tubers (Solanum tuberosum L.)

Background

Wound healing is a representative phenomenon of potato tubers subjected to mechanical injuries. Our previous results found that benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH) promoted the wound healing of potato tubers. However, the molecular mechanism related to inducible wound healing remains unknown.

Results

Transcriptomic evaluation of healing tissues from potato tubers at three stages, namely, 0 d (nonhealing), 5 d (wounded tubers healed for 5 d) and 5 d (BTH-treated tubers healed for 5 d) using RNA-Seq and differentially expressed genes (DEGs) analysis showed that more than 515 million high-quality reads were generated and a total of 7665 DEGs were enriched, and 16 of these DEGs were selected by qRT-PCR analysis to further confirm the RNA sequencing data. Gene ontology (GO) enrichment analysis indicated that the most highly DEGs were involved in metabolic and cellular processes, and KEGG enrichment analysis indicated that a large number of DEGs were associated with plant hormones, starch and sugar metabolism, fatty acid metabolism, phenylpropanoid biosynthesis and terpenoid skeleton biosynthesis. Furthermore, a few candidate transcription factors, including MYB, NAC and WRKY, and genes related to Ca²⁺-mediated signal transduction were also found to be differentially expressed during wound healing. Most of these enriched DEGs were upregulated after BTH treatment.

Conclusion

This comparative expression profile provided useful resources for studies of the molecular mechanism via these promising candidates involved in natural or elicitor-induced wound healing in potato tubers.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-022-08480-1.