| 1. |
- Bhalerao, Rishikesh P.
(författare)
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Effect of the photoperiod on bud dormancy in Liriodendron chinense
- 2022
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Ingår i: Journal of Plant Physiology. - : Elsevier BV. - 0176-1617 .- 1618-1328. ; 279
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Tidskriftsartikel (refereegranskat)abstract
- Bud dormancy and its release are complex physiological phenomena in plants. The molecular mechanisms of bud dormancy in Liriodendron chinense are mainly unknown. Here, we studied bud dormancy and the related phys-iological and molecular phenomena in Liriodendron under long-day (LD) and short-day (SD). Bud burst was released faster under LD than under SD. Abscisic acid (ABA), superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GR) activities were increased significantly under LD in Liriodendron buds. In contrast, the contents of gibberellic acid (GA3), ascorbic acid (AsA), glutathione (GSH), malondialdehyde (MDA), and ascorbate peroxidase (APX) activity decreased under LD but increased under SD. Differentially expressed genes (DEGs) were up-regulated under LD and down-regulated under SD and these changes correspondingly promoted (LD) or repressed (SD) cell division and the number and/or size of cells in the bud. Transcriptomic analysis of Liriodendron buds under different photoperiods identified 187 DEGs enriched in several pathways such as flavonoid biosynthesis and phenylpropanoid biosynthesis, plant hormone and signal transduction, etc. that are associated with antioxidant enzymes, non-enzymatic antioxidants, and subsequently promote the growth of the buds. Our findings provide novel insights into regulating bud dormancy via flavonoid and phenylpropanoid biosynthesis, plant hormone and signal transduction pathways, and ABA content. These physiological and biochemical traits would help detect bud dormancy in plants.
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| 2. |
- Chardon, Fabien, et al.
(författare)
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Natural variation in the long-distance transport of nutrients and photoassimilates in response to N availability
- 2022
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Ingår i: Journal of plant physiology (Print). - : Elsevier. - 0176-1617 .- 1618-1328. ; 273
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Tidskriftsartikel (refereegranskat)abstract
- Phloem and xylem tissues are necessary for the allocation of nutrients and photoassimilates. However, how the long-distance transport of carbon (C) and nitrogen (N) is coordinated with the central metabolism is largely unknown. To better understand how the genetic and environmental factors influence C and N transport, we analysed the metabolite profiles of phloem exudates and xylem saps of five Arabidopsis thaliana accessions grown in low or non-limiting N supply. We observed that xylem saps were composed of 46 or 56% carbohydrates, 27 or 45% amino acids, and 5 or 13% organic acids in low or non-limiting N supply, respectively. In contrast, phloem exudates were composed of 76 or 86% carbohydrates, 7 or 18% amino acids, and 5 or 6% organic acids. Variation in N supply impacted amino acid, organic acid and sugar contents. When comparing low N and non-limiting N, the most striking differences were variations of glutamine, aspartate, and succinate abundance in the xylem saps and citrate and fumarate abundance in phloem exudates. In addition, we observed a substantial variation of metabolite content between genotypes, particularly under high N. The content of several organic acids, such as malate, citrate, fumarate, and succinate was affected by the genotype alone or by the interaction between genotype and N supply. This study confirmed that the response of the transport of nutrients in the phloem and the xylem to N availability is associated with the regulation of the central metabolism and could be an adaptive trait.
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| 3. |
- Kleczkowski, Leszek A., 1954-, et al.
(författare)
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Magnesium and cell energetics : at the junction of metabolism of adenylate and non-adenylate nucleotides
- 2023
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Ingår i: Journal of plant physiology (Print). - : Elsevier. - 0176-1617 .- 1618-1328. ; 280
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Tidskriftsartikel (refereegranskat)abstract
- Free magnesium (Mg2+) represents a powerful signal arising from interconversions of adenylates (ATP, ADP and AMP). This is a consequence of the involvement of adenylate kinase (AK) which equilibrates adenylates and uses defined species of Mg-complexed and Mg-free adenylates in both directions of its reaction. However, cells contain also other reversible Mg2+-dependent enzymes that equilibrate non-adenylate nucleotides (uridylates, cytidylates and guanylates), i.e. nucleoside monophosphate kinases (NMPKs) and nucleoside diphosphate kinase (NDPK). Here, we propose that AK activity is tightly coupled to activities of NMPK and NDPK, linking adenylate equilibrium to equilibria of other nucleotides, and with [Mg2+] controlling the ratios of Mg-chelated and Mg-free nucleotides. This coupling establishes main hubs for adenylate-driven equilibration of non-adenylate nucleotides, with [Mg2+] acting as signal arising from all nucleotides rather than adenylates only. Further consequences involve an overall adenylate control of UTP-, GTP- and CTP-dependent pathways and the availability of substrates for RNA and DNA synthesis.
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