CmOr golden SNP dramatically affects carotenoid content and plastid fate in melon by inhibiting metabolism downstream of β-carotene.

Phosphorus is an important macronutrient for plant growth, but often deficient in soil. To understand the molecular basis of the complex responses of potato (Solanum tuberosum L.) to phosphate (Pi) deficiency stress, the RNA-Seq approach was taken to identify genes responding to Pi starvation in potato roots. A total of 359 differentially expressed genes were identified, among which the Solanum tuberosum transcription factor gene MYB44 (StMYB44) was found to be down-regulated by Pi starvation. StMYB44 was ubiquitously expressed in potato tissues and organs, and StMYB44 protein was exclusively localized in the nucleus. Overexpression of StMYB44 in potato resulted in lower accumulation of Pi in shoots. Transcriptomic analysis indicated that the abundance of S. tuberosum PHOSPHATE1 (StPHO1), a Pi transport-related gene, was reduced in StMYB44 overexpression lines. In contrast, knock-out of StMYB44 by a CRISPR/Cas9 system failed to increase transcription of StPHO1. Moreover, StMYB44 was found to interact in the nucleus with AtWRKY6, a known Arabidopsis transcription factor directly regulating PHO1 expression, and StWRKY6, indicating that StMYB44 could be a member of the regulatory complex controlling transcription of StPHO1. Taken together, our study demonstrates that StMYB44 negatively regulates Pi transport in potato by suppressing StPHO1 expression.

Recent heterograft analyses showed that large-scale messenger RNA (mRNA) movement takes place in the phloem, but the number of mobile transcripts reported varies widely. However, our knowledge of the mechanisms underlying large-scale mRNA movement remains limited. In this study, using a Nicotiana benthamiana/tomato (Solanum lycopersicum) heterograft system and a transgenic approach involving potato (Solanum tuberosum), we found that: (1) the overall mRNA abundance in the leaf is not a good indicator of transcript mobility to the root; (2) increasing the expression levels of nonmobile mRNAs in the companion cells does not promote their mobility; (3) mobile mRNAs undergo degradation during their movement; and (4) some mRNAs arriving in roots move back to shoots. These results indicate that mRNA movement has both regulated and unregulated components. The cellular origins of mobile mRNAs may differ between herbaceous and woody species. Taken together, these findings suggest that the long-distance movement of mRNAs is a complex process and that elucidating the physiological roles associated with this movement is challenging but remains an important task for future research.

Garlic (Allium sativum L.) is an economically important, monocotyledonous plant with a strong taste and odor. Drought stress adversely affects its growth, development, and yield, particularly during the bolting/bulbing stage. Herein we performed RNA-seq to assess transcriptomic changes induced by drought stress in bolting/bulbing hardneck garlic plants (Purple Glazer). We observed that drought stress significantly reduced photosynthesis rate, fresh weight, and leaf water content. Transcriptomic analysis of garlic leaves under normal conditions and drought stress led to the identification of 5215 differentially expressed genes (2748 up- and 2467 downregulated). The upregulated DEGs were primarily involved in “biological process”, “metabolic process”, “oxidation-reduction process”, carbohydrate and lipid metabolism, and “proteolysis”, whereas the downregulated DEGs were mainly involved in “biological process” and metabolism of various molecules. In addition, genes encoding abscisic acid biosynthetic and catabolic enzymes, heat shock proteins, and E3 ubiquitin ligases were significantly altered by drought stress, indicating involvement in drought tolerance. A further comparison with the DEGs related to salinity stress-treated garlic revealed 867 and 305 DEGs with a similar and reverse expression alteration tendency, respectively.

Blue lasers are becoming more widely used in the diagnosis and treatment of bladder cancer; however, their photobiomodulation effects on bladder cancer cells remains unclear. The purpose of the current study was to explore the photobiomodulation effect of blue laser irradiation on bladder cancer progression and the associated mechanisms. The human uroepithelial cell line SV-HUC-1 and human bladder cancer cell lines T24 and EJ were exposed to blue laser irradiation (450 nm) at various energy densities, and cell proliferation, migration, invasion, epithelial-mesenchymal transition (EMT), and the levels of the proteins associated with the MAPK pathway proteins were determined. A significant decrease in cell viability was observed in a density-dependent manner after blue laser irradiation at > 4 J/cm² in both bladder cancer cell lines. However, the blue laser did not reduce cell viability in SV-HUC-1 cells until the energy density exceeded 16 J/cm². Meanwhile, Ki67 levels, reflecting cell proliferation and senescence, were also significantly decreased after blue laser irradiation at 4 J/cm² and 8 J/cm² in the absence of cell cycle arrest. Moreover, blue laser irradiation at 4 J/cm² and 8 J/cm² caused a reduction in cell migration and invasion and also reduced the expression levels of MMP-2, MMP-9, Snail, N-cadherin, phospho-MEK and phospho-ERK, and elevated the expression levels of E-cadherin. Meanwhile ERK activator(tBHQ) significantly reversed the irradiation-induced suppression of proliferation, migration and invasion in T24 and EJ cell lines. The present study showed that blue laser irradiation inhibited bladder cancer proliferation in a density-dependent manner and inhibited bladder cancer progression by suppressing migration, invasion, and the EMT process in T24 and EJ cell lines. This inhibition was possibly mediated via suppression of the MAPK/MEK/ERK pathway. Thus, the use of a low-energy blue laser in the diagnosis and treatment of bladder cancer is possibly safe and may have an anti-tumor effect.

To examine physiological responses of garlic to salinity, 17-day-old seedlings of eight soft-neck accessions were treated with 200 mM NaCl for seven days in a hydroponic system. Several morphological and physiological traits were measured at the end of the treatment, including shoot height, shoot fresh weight, shoot dry weight, root length, root fresh weight, root dry weight, photosynthesis rate, and concentrations of Na⁺ and K⁺ in leaves. The principal component analysis showed that shoot dry weight and K⁺/Na⁺ ratio contribute the most to salt tolerance among the garlic accessions. As a result, salt-tolerant and sensitive accessions were grouped based on these two parameters. Furthermore, to investigate the molecular mechanisms in garlic in response to salinity, the transcriptomes of leaves and roots between salt-tolerant and salt-sensitive garlic accessions were compared. Approximately 1.5 billion read pairs were obtained from 24 libraries generated from the leaves and roots of the salt-tolerant and salt-sensitive garlic accessions. A total of 47,509 genes were identified by mapping the cleaned reads to the garlic reference genome. Statistical analysis indicated that 1282 and 1068 genes were upregulated solely in the tolerant leaves and roots, whereas 1505 and 1203 genes were downregulated exclusively in the tolerant leaves and roots after NaCl treatment, respectively. Functional categorization of these genes revealed their involvement in a variety of biological processes. Several genes important for carotenoid biosynthesis, auxin signaling, and K⁺ transport were strongly altered in roots by NaCl treatment and could be candidate genes for garlic salt tolerance improvement.