![]() ![]() #Sap 2000 fa > fe free#In addition, excessive accumulation of free amino acids, especially proline, has been reported for tobacco ( Ren et al., 2016), cotton ( Hu et al., 2017), oilseed rape ( Lu et al., 2019), barley ( Zeng et al., 2018), and Arabidopsis ( Armengaud et al., 2009). It can lead to increases in the concentrations of free sugars in the leaves of bean ( Cakmak et al., 1994), cotton ( Bednarz and Oosterhuis, 1999 Pettigrew, 1999 Hu et al., 2017), potato ( Koch et al., 2018), and oilseed rape ( Pan et al., 2017), the roots of alfalfa ( Jungers et al., 2019), rice ( Ma et al., 2012 Chen et al., 2015), and sugar beet ( Aksu and Altay, 2020), and the leaves and the roots of Arabidopsis ( Armengaud et al., 2009), barley ( Zeng et al., 2018), and tomato ( Sung et al., 2015). K deficiency is a common abiotic stress in agricultural production ( Hosseini et al., 2017 Xu et al., 2020). Its levels affect those of primary and secondary metabolites in plants ( Armengaud et al., 2009 Coskun et al., 2017 Chatterjee et al., 2020). K is involved directly or indirectly in plant protein and sugar metabolism ( Chen et al., 2018 Andrea et al., 2020) and is required by more than 60 enzymes as a cofactor ( Hawkesford et al., 2012 Vašák and Schnabl, 2016). ![]() It rather plays important roles in plant cells (e.g., expansion, turgor pressure, and osmo-regulation) and is involved in metabolism, growth, yield, and the opening and the closing of stomata in response to abiotic and biotic stresses ( Hasanuzzaman et al., 2018 Chérel and Gaillard, 2019). ![]() Potassium (K) is a macronutrient, and unlike nitrate, phosphate, and sulfate, it is not assimilated into organic matter. This study lays a solid foundation for further research on targeted metabolites and signal substances in the xylem sap of cotton plants exposed to K deficiency. This eventually resulted in decreased biomass of cotton seedlings under LK stress. Overall, K deficiency reduced the antioxidant capacity of cotton seedlings and led to a metabolic disorder including elevated levels of primary metabolites and inhibited production of secondary metabolites. ![]() Furthermore, in pathway analyses, 26 metabolites were matched to Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways L-aspartic acid, which was associated with 10 KEGG pathways, was the most involved metabolite. It is worth noting that glycerophosphocholine was up-regulated 29-fold under LK stress, indicating that it can be used as an important signal of root–shoot communication. In particular, several metabolites found in the cell membrane including three cholines (glycerophosphatecholine, 2-hexenylcholine, and caproylcholine) and desglucocoroloside and others such as malondialdehyde, α-amino acids and derivatives, sucrose, and sugar alcohol significantly increased under LK stress, indicating that cell membranes were damaged and protein metabolism was abnormal. A total of 82 metabolites in sap analyzed by high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) showed significant differences between the two conditions among these, 38 were up-regulated more than 2-fold, while the others were down-regulated less than 0.5-fold. Compared to control, LK stress significantly decreased seedling biomass (leaf, stem, and root dry weight stem and root length root surface area and root volume) and the levels of K, Na (sodium), Mg (magnesium), Fe (iron), and Zn (zinc) in xylem sap. In particular, we compared changes in root–shoot communication under low K (LK) and normal K (NK, control) levels. This study investigated the effects of potassium (K) deficiency on the morphology and the physiology of cotton seedlings as well as pH, mineral nutrient contents, and metabolites of xylem sap. Xylem sap, belonging to the plant apoplast, not only provides plant tissues with inorganic and organic substances but also facilitates communication between the roots and the leaves and coordinates their development. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |