Effect of Overexpression of γ-Tocopherol Methyltransferase on α-Tocopherol and Fatty Acid Accumulation and Tolerance to Salt Stress during Seed Germination in Brassica napus L

The varying responses of leaves and roots and the link between sugar metabolic genes and the SWEET family in Dendrobium officinale under salt stress

BACKGROUND

Dendrobium officinale Kimura et Migo is a perennial epiphytic herb in traditional Chinese medicine, showing remarkable resistance to salt stress. Water-soluble sugars serve as important osmoprotectants and play crucial roles in plant stress responses. Previous studies have primarily focused on sugar metabolism in individual tissues under stress, resulting in a limited understanding of the regulatory differences between tissues and the relationship between sugar metabolism and transport.

RESULTS

A variety of salt-responsive genes were identified through transcriptome analysis of D. officinale. GO and KEGG enrichment analyses revealed functional differences among the differentially expressed genes (DEGs) between leaves and roots. Expression analysis indicated that sugar metabolic genes and D. officinale Sugars Will Eventually be Exported Transporters (DoSWEETs) displayed distinct expression patterns in leaves and roots under salt stress. Most sugar metabolic genes were up-regulated in the leaves and down-regulated in the roots in response to salt, while DoSWEETs predominantly responded in the roots. Specifically, DoSWEET2a, 6a, 12a, 14, and 16 were confirmed via RT-qPCR. Additionally, positive correlations were observed between certain genes (scrK, INV, SUS) and DoSWEETs, with INV (LOC110096666) showing a strong positive correlation with all detected DoSWEETs in both leaves and roots.

CONCLUSIONS

Our findings not only illustrated the distinct responses of leaves and roots to salt stress, but also highlighted the relationship between sugar metabolic genes and DoSWEETs in adapting to such stress. This enhances our understanding of the differential responses of plant tissues to salt stress and identified candidate genes for salt-resistance breeding in D. officinale.

Anticancer Potential of Tocopherols-Containing Plants and Semi-Synthetic Tocopherols

Tocopherols, potent bioactive compounds with anticancer properties, remain understudied in herbal medicinal plants, presenting a significant knowledge gap in the field of natural anticancer agents. This review evaluates tocopherol-containing plants for their anticancer potential, analyzing Scopus publications from 2016 to 2024. Fifteen herbal medicinal plants were identified as promising candidates, including Bulbine anguistifolia Poelln, Punica granatum L., Moringa oleifera, Kigelia pinnata, and Typhonium flagelliforme Lodd. The review explores tocopherols' anticancer mechanisms, including apoptosis induction and cell cycle arrest. Factors influencing tocopherols' anticancer effects are examined, such as their forms (α, β, γ, δ), concentrations, plant parts utilized, and their stability in various plants. Additionally, emerging research on semi-synthetic tocopherol derivatives is analyzed, highlighting their potential as adjuvants in chemotherapy and their role in enhancing drug delivery and reducing side effects. This comprehensive analysis aims to advance the development of plant-based anticancer pharmaceuticals and improve cancer treatment strategies. By elucidating the mechanisms and potential of tocopherol-containing plants, this review provides a foundation for future research in plant-based anticancer therapies. It emphasizes the need for further investigation into these plants' anticancer properties, potentially leading to novel, more effective, and less toxic cancer therapies. The findings presented here contribute to a nuanced understanding of how tocopherol-containing plants can be leveraged in the development of future anticancer drugs.

Identification of QTNs, QTN-by-environment interactions, and their candidate genes for salt tolerance related traits in soybean

BACKGROUND

Salt stress significantly reduces soybean yield. To improve salt tolerance in soybean, it is important to mine the genes associated with salt tolerance traits.

RESULTS

Salt tolerance traits of 286 soybean accessions were measured four times between 2009 and 2015. The results were associated with 740,754 single nucleotide polymorphisms (SNPs) to identify quantitative trait nucleotides (QTNs) and QTN-by-environment interactions (QEIs) using three-variance-component multi-locus random-SNP-effect mixed linear model (3VmrMLM). As a result, eight salt tolerance genes (GmCHX1, GsPRX9, Gm5PTase8, GmWRKY, GmCHX20a, GmNHX1, GmSK1, and GmLEA2-1) near 179 significant and 79 suggested QTNs and two salt tolerance genes (GmWRKY49 and GmSK1) near 45 significant and 14 suggested QEIs were associated with salt tolerance index traits in previous studies. Six candidate genes and three gene-by-environment interactions (GEIs) were predicted to be associated with these index traits. Analysis of four salt tolerance related traits under control and salt treatments revealed six genes associated with salt tolerance (GmHDA13, GmPHO1, GmERF5, GmNAC06, GmbZIP132, and GmHsp90s) around 166 QEIs were verified in previous studies. Five candidate GEIs were confirmed to be associated with salt stress by at least one haplotype analysis. The elite molecular modules of seven candidate genes with selection signs were extracted from wild soybean, and these genes could be applied to soybean molecular breeding. Two of these genes, Glyma06g04840 and Glyma07g18150, were confirmed by qRT-PCR and are expected to be key players in responding to salt stress.

CONCLUSIONS

Around the QTNs and QEIs identified in this study, 16 known genes, 6 candidate genes, and 8 candidate GEIs were found to be associated with soybean salt tolerance, of which Glyma07g18150 was further confirmed by qRT-PCR.

Harnessing γ-TMT Genetic Variations and Haplotypes for Vitamin E Diversity in the Korean Rice Collection

Gamma-tocopherol methyltransferase (γ-TMT), a key gene in the vitamin E biosynthesis pathway, significantly influences the accumulation of tocochromanols, thereby determining rice nutritional quality. In our study, we analyzed the γ-TMT gene in 475 Korean rice accessions, uncovering 177 genetic variants, including 138 SNPs and 39 InDels. Notably, two functional SNPs, tmt-E2-28,895,665-G/A and tmt-E4-28,896,689-A/G, were identified, causing substitutions from valine to isoleucine and arginine to glycine, respectively, across 93 accessions. A positive Tajima's D value in the indica group suggests a signature of balancing selection. Haplotype analysis revealed 27 haplotypes, with two shared between cultivated and wild accessions, seven specific to cultivated accessions, and 18 unique to wild types. Further, profiling of vitamin E isomers in 240 accessions and their association with haplotypes revealed that Hap_2, distinguished by an SNP in the 3' UTR (tmt-3UTR-28,897,360-T/A) exhibited significantly lower α-tocopherol (AT), α-tocotrienol (AT3), total tocopherol, and total tocotrienol, but higher γ-tocopherol (GT) in the japonica group. Additionally, in the indica group, Hap_2 showed significantly higher AT, AT3, and total tocopherol, along with lower GT and γ-tocotrienol, compared to Hap_19, Hap_20, and Hap_21. Overall, this study highlights the genetic landscape of γ-TMT and provides a valuable genetic resource for haplotype-based breeding programs aimed at enhancing nutritional profiles.

Targeted mutagenesis of BnTTG1 homologues generated yellow-seeded rapeseed with increased oil content and seed germination under abiotic stress

Yellow seed is one desirable trait with great potential to improve seed oil quality and yield. The present study surveys the redundant role of BnTTG1 genes in the proanthocyanidins (PA) biosynthesis, oil content and abiotic stress resistance. Stable yellow seed mutants were generated after mutating BnTTG1 by CRISPR/Cas9 genome editing system. Yellow seed phenotype could be obtained only when both functional homologues of BnTTG1 were simultaneously knocked out. Homozygous mutants of BnTTG1 homologues showed decreased thickness and PA accumulation in seed coat. Transcriptome and qRT-PCR analysis indicated that BnTTG1 mutation inhibited the expression of genes involved in phenylpropanoid and flavonoid biosynthetic pathways. Increased seed oil content and alteration of fatty acid (FA) composition were observed in homozygous mutants of BnTTG1 with enriched expression of genes involved in FA biosynthesis pathway. In addition, target mutation of BnTTG1 accelerated seed germination rate under salt and cold stresses. Enhanced seed germination capacity in BnTTG1 mutants was correlated with the change of expression level of ABA responsive genes. Overall, this study elucidated the redundant role of BnTTG1 in regulating seed coat color and established an efficient approach for generating yellow-seeded oilseed rape genetic resources with increase oil content, modified FA composition and resistance to multiple abiotic stresses.

Molecular Genetics Enhances Plant Breeding

Human-driven plant selection, a practice as ancient as agriculture itself, has laid the foundations of plant breeding and contemporary farming [...].