Victória Carvalho, Paula Natália Pereira, Bruno Nobuya Katayama Gobara, Marília Gaspar, Helenice Mercier
{"title":"Ammonium induces aquaporin gene expression in Guzmania monostachia (Bromeliaceae) under drought","authors":"Victória Carvalho, Paula Natália Pereira, Bruno Nobuya Katayama Gobara, Marília Gaspar, Helenice Mercier","doi":"10.1007/s40626-024-00344-1","DOIUrl":null,"url":null,"abstract":"<p>The leaves of <i>Guzmania monostachia</i>, a tank epiphytic bromeliad, present a functional division: the base performs water and nutrient uptake through absorbing trichomes, while the apex presents higher photosynthetic activity and nitrogen (N) assimilation. Drought conditions induce Crassulacean acid metabolism (CAM) in the apex portion, with N nutrition influencing this process. Ammonium (NH<sub>4</sub><sup>+</sup>) induces higher CAM activity, reducing greater water loss compared to nitrate (NO<sub>3</sub><sup>−</sup>). Aquaporins play a crucial role in regulating membrane permeability in leaf tissues under drought. This study aimed to evaluate how different N sources (NO<sub>3</sub><sup>−</sup> and NH<sub>4</sub><sup>+</sup>) in combination with drought affect the diurnal gene expression of aquaporins along the leaf blade of <i>G. monostachia</i>. Detached leaves were immersed in 30% (w/v) polyethylene glycol 6000 solution containing NO<sub>3</sub><sup>−</sup> or NH<sub>4</sub><sup>+</sup> for 7 days. Leaf apexes and bases were harvested at dawn and dusk. At dawn, NH<sub>4</sub><sup>+</sup> improved water conservation and upregulated the expression of five aquaporin genes in the apex compared to NO<sub>3</sub><sup>−</sup>, including <i>GmNIP5;1</i>. In the leaf base at dawn, <i>GmNIP5;1</i> was the most upregulated gene by NH<sub>4</sub><sup>+</sup>, suggesting its involvement in NH<sub>4</sub><sup>+</sup> transport to the apex, intensifying CAM and other aquaporin genes' expression under drought. At dusk, NH<sub>4</sub><sup>+</sup> led to pronounced downregulation of <i>TIPs</i> and <i>NIPs</i> than NO<sub>3</sub><sup>−</sup> in both leaf portions, possibly ensuring lower membrane permeability and higher water retention during drought. These results offer valuable insights for future studies on the functions of aquaporins in drought tolerance and nitrogen-use efficiency in plants.</p>","PeriodicalId":23038,"journal":{"name":"Theoretical and Experimental Plant Physiology","volume":"6 1","pages":""},"PeriodicalIF":2.2000,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Theoretical and Experimental Plant Physiology","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1007/s40626-024-00344-1","RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PLANT SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
The leaves of Guzmania monostachia, a tank epiphytic bromeliad, present a functional division: the base performs water and nutrient uptake through absorbing trichomes, while the apex presents higher photosynthetic activity and nitrogen (N) assimilation. Drought conditions induce Crassulacean acid metabolism (CAM) in the apex portion, with N nutrition influencing this process. Ammonium (NH4+) induces higher CAM activity, reducing greater water loss compared to nitrate (NO3−). Aquaporins play a crucial role in regulating membrane permeability in leaf tissues under drought. This study aimed to evaluate how different N sources (NO3− and NH4+) in combination with drought affect the diurnal gene expression of aquaporins along the leaf blade of G. monostachia. Detached leaves were immersed in 30% (w/v) polyethylene glycol 6000 solution containing NO3− or NH4+ for 7 days. Leaf apexes and bases were harvested at dawn and dusk. At dawn, NH4+ improved water conservation and upregulated the expression of five aquaporin genes in the apex compared to NO3−, including GmNIP5;1. In the leaf base at dawn, GmNIP5;1 was the most upregulated gene by NH4+, suggesting its involvement in NH4+ transport to the apex, intensifying CAM and other aquaporin genes' expression under drought. At dusk, NH4+ led to pronounced downregulation of TIPs and NIPs than NO3− in both leaf portions, possibly ensuring lower membrane permeability and higher water retention during drought. These results offer valuable insights for future studies on the functions of aquaporins in drought tolerance and nitrogen-use efficiency in plants.
期刊介绍:
The journal does not publish articles in taxonomy, anatomy, systematics and ecology unless they have a physiological approach related to the following sections:
Biochemical Processes: primary and secondary metabolism, and biochemistry;
Photobiology and Photosynthesis Processes;
Cell Biology;
Genes and Development;
Plant Molecular Biology;
Signaling and Response;
Plant Nutrition;
Growth and Differentiation: seed physiology, hormonal physiology and photomorphogenesis;
Post-Harvest Physiology;
Ecophysiology/Crop Physiology and Stress Physiology;
Applied Plant Ecology;
Plant-Microbe and Plant-Insect Interactions;
Instrumentation in Plant Physiology;
Education in Plant Physiology.