How Cysteine Protease Gene PtCP5 Affects Seed Germination by Mobilizing Storage Proteins in Populus trichocarpa

Identifying a cis-element in PtoCP1 promoter for efficiently controlling constitutive gene expression in Populus tomentosa

Gene expression is regulated by transcription factors binding to cis-elements in promoters. However, efficient cis-elements for genetic engineering are rarely reported. In this study, we identified an 11 bp cis-element in the PtoCP1 promoter that drives strong constitutive gene expression in Populus tomentosa. A 2,270 bp promoter region upstream of the PtoCP1 gene's translation start site was cloned and named ProPtoCP1. This promoter controls GUS reporter gene expression in the roots, leaves, and stems of Arabidopsis seedlings. Based on the location and density of cis-elements, the PtoCP1 promoter was divided into four fragments by 5'-end deletions. GUS staining and RT-qPCR revealed a key cis-element at -466 to -441 bp essential for gene expression. Further analysis showed that the MYB-TGACG cis-element is a positive regulator, whereas neither MYB nor TGACG alone drove gene expression. This study enhances our understanding of gene expression regulation by cis-elements and provides a valuable tool for genetic engineering.

Uncovering seed vigor responsive miRNA in hybrid wheat and its parents by deep sequencing

BACKGROUND

Two-line hybrid wheat technology system is one way to harness wheat heterosis both domestically and internationally. Seed vigor is a crucial parameter for assessing seed quality, as enhanced seed vigor can lead to yield increments of over 20% to a certain extent. MicroRNAs (miRNAs) were known to participate in the development and vigor of seed in plants, but its impact on seed vigor in two-line hybrid wheat remains poorly elucidated.

RESULTS

The hybrid (BS1453/11GF5135) wheat exhibited superiority in seed vigor and anti-aging capacity, compared to its male parent (11GF5135, MP) and female parent (BS1453, FP). We identified four miRNAs associated with seed vigor, all of which are novel miRNAs. The majority of targets of miRNAs were related to ubiquitin ligases, kinases, sucrose synthases and hydrolases, involving in starch and sucrose metabolism, hydrolysis, catalysis, plant hormone signal transduction, and other pathways, which played crucial roles in seed development. Additionally, we also found miR531 was differentially expressed in both male parent and hybrid, and its target gene was a component of the E1 subunit of α-ketoate dehydrogenase complex, which interacted with dihydrolipoamide acetyltransferase (E2) and dihydrolipoyl dehydrogenase (E3). Finally, We established a presumptive interaction model to speculate the relationship of miR531 and seed vigor.

CONCLUSIONS

This study analyzed the seed vigor of two-line hybrid wheat, and screened seed vigor-related miRNAs. Meanwhile speculated the genetic relationship of hybrid and parents, in terms of miRNAs. Consequently, the present study provides new insights into the miRNA-mediated gene and protein interaction network that regulates seed vigor. These findings hold significance for enhancing the yield and quality of two-line hybrid wheat, facilitating its future applications.

In order to lower the antinutritional activity of serine protease inhibitors, we need to understand their role in seed development

Proteases, including serine proteases, are involved in the entire life cycle of plants. Proteases are controlled by protease inhibitors (PI) to limit any uncontrolled or harmful protease activity. The role of PIs in biotic and abiotic stress tolerance is well documented, however their role in various other plant processes has not been fully elucidated. Seed development is one such area that lack detailed work on the function of PIs despite the fact that this is a key process in the life cycle of the plant. Serine protease inhibitors (SPI) such as the Bowman-Birk inhibitors and Kunitz-type inhibitors, are abundant in legume seeds and act as antinutrients in humans and animals. Their role in seed development is not fully understood and present an interesting research target. Whether lowering the levels and activity of PIs, in order to lower the anti-nutrient levels in seed will affect the development of viable seed, remains an important question. Studies on the function of SPI in seed development are therefore required. In this Perspective paper, we provide an overview on the current knowledge of seed storage proteins, their degradation as well as on the serine protease-SPI system in seeds and what is known about the consequences when this system is modified. We discuss areas that require investigation. This includes the identification of seed specific SPIs; screening of germplasms, to identify plants with low seed inhibitor content, establishing serine protease-SPI ratios and lastly a focus on molecular techniques that can be used to modify seed SPI activity.

A Genome Wide Association Study Revealed Key Single Nucleotide Polymorphisms/Genes Associated With Seed Germination in Gossypium hirsutum L

Fast and uniform seed germination is essential to stabilize crop yields in agricultural production. It is important to understand the genetic basis of seed germination for improving the vigor of crop seeds. However, little is known about the genetic basis of seed vigor in cotton. In this study, we evaluated four seed germination-related traits of a core collection consisting of 419 cotton accessions, and performed a genome-wide association study (GWAS) to explore important loci associated with seed vigor using 3.66 million high-quality single nucleotide polymorphisms (SNPs). The results showed that four traits, including germination potential, germination rate, germination index, and vigor index, exhibited broad variations and high correlations. A total of 92 significantly associated SNPs located within or near 723 genes were identified for these traits, of which 13 SNPs could be detected in multiple traits. Among these candidate genes, 294 genes were expressed at seed germination stage. Further function validation of the two genes of higher expression showed that Gh_A11G0176 encoding Hsp70-Hsp90 organizing protein negatively regulated Arabidopsis seed germination, while Gh_A09G1509 encoding glutathione transferase played a positive role in regulating tobacco seed germination and seedling growth. Furthermore, Gh_A09G1509 might promote seed germination and seedling establishment through regulating glutathione metabolism in the imbibitional seeds. Our findings provide unprecedented information for deciphering the genetic basis of seed germination and performing molecular breeding to improve field emergence through genomic selection in cotton.