Physiological and biochemical studies on aluminum tolerance in pineapple

Soil Research ◽  
2004 ◽  
Vol 42 (6) ◽  
pp. 699 ◽  
Author(s):  
H. Le Van ◽  
T. Masuda

Aluminum is rhizotoxic and is often present in acidic soils at activities high enough to inhibit root growth. The objectives of present study were to screen for Al-sensitive and Al-tolerant pineapple (Ananas comosus (L.) Merrill) cultivars and to investigate the potential mechanism(s) of Al tolerance. Seven cultivars were analysed and found to differ considerably in Al tolerance. The cultivars Soft Touch (Al-sensitive) and Cayenne (Al-tolerant) were selected for further analysis of physiological mechanism(s) of Al tolerance. The root elongation of Soft Touch was 80% compared with 120% for Cayenne in response to 300 μm AlCl3 at pH 4.5 for 72 h. Al accumulation and Al-induced callose formation in root apices were 50 and 15% of that in Cayenne, respectively. It is clearly shown that Al only inhibited Soft Touch during the treatment, whereas it enhanced root growth of Cayenne, suggesting an Al-induced Al-tolerance mechanism operating in Cayenne. There was no significantly difference in total protein in root exudates between cultivars treated with or without 300 μm AlCl3. However, 2D SDS–PAGE analysis could detect an acidic and low molecular weight protein in Al-treated Cayenne root tips, but not in control Cayenne or in Soft Touch both in the presence and absence of Al. The identification of organic acids in collected root exudates was conducted on Al-tolerant Cayenne. Citrate, malate, and succinate were found in Cayenne root exudates, and citrate was induced by Al exposure. Changes in organic acids from root exudates and soluble protein of root tips may be involved in the Al-tolerance mechanism. Further studies are, however, needed to clarify their functions on detoxification of Al in the pineapple roots.

Author(s):  
Xia Zhang ◽  
Brayden Weir ◽  
Hongru Wei ◽  
Zhiwei Deng ◽  
Xiaoqi Zhang ◽  
...  

AbstractChickpea is an economically important legume crop with high nutritional value in human diets. Aluminium-toxicity poses a significant challenge for the yield improvement of this increasingly popular crop in acidic soils. The wild progenitors of chickpea may provide a more diverse gene pool for Al-tolerance in chickpea breeding. However, the genetic basis of Al-tolerance in chickpea and its wild relatives remains largely unknown. Here, we assessed the Al-tolerance of six selected wild Cicer accessions by measuring the root elongation in solution culture under control (0 µM Al3+) and Al-treatment (30 µM Al3+) conditions. Al-treatment significantly reduced the root elongation in all target lines compared to the control condition after 2-day’s growth. However, the relative reduction of root elongation in different lines varied greatly: 3 lines still retained significant root growth under Al-treatment, whilst another 2 lines displayed no root growth at all. We performed genome-wide identification of multidrug and toxic compound extrusion (MATE) encoding genes in the Cicer genome. A total of 56 annotated MATE genes were identified, which divided into 4 major phylogeny groups (G1-4). Four homologues to lupin LaMATE (> 50% aa identity; named CaMATE1-4) were clustered with previously characterised MATEs related to Al-tolerance in various other plants. qRT-PCR showed that CaMATE2 transcription in root tips was significantly up-regulated upon Al-treatment in all target lines, whilst CaMATE1 was up-regulated in all lines except Bari2_074 and Deste_064, which coincided with the lines displaying no root growth under Al-treatment. Transcriptional profiling in five Cicer tissues revealed that CaMATE1 is specifically transcribed in the root tissue, further supporting its role in Al-detoxification in roots. This first identification of MATE-encoding genes associated with Al-tolerance in Cicer paves the ways for future functional characterization of MATE genes in Cicer spp., and to facilitate future design of gene-specific markers for Al-tolerant line selection in chickpea breeding programs.


2004 ◽  
Vol 24 (11) ◽  
pp. 1267-1277 ◽  
Author(s):  
I. R. Silva ◽  
R. F. Novais ◽  
G. N. Jham ◽  
N. F. Barros ◽  
F. O. Gebrim ◽  
...  

2003 ◽  
Vol 54 (10) ◽  
pp. 979 ◽  
Author(s):  
X. G. Zhang ◽  
R. S. Jessop ◽  
D. Alter

Three triticale cultivars differing in aluminium (Al) stress response, together with 1 Al-tolerant wheat cultivar (Carazinho) and 1 Al-tolerant wheat line (ET3), were used to investigate the root exudation of organic acids during Al stress. The likely relationship of organic acid exudation with Al tolerance, as assessed by root regrowth in nutrient solutions, was also examined. An enzymatic assay was used to detect malate release from both root tips and the whole root system; high performance liquid chromatography (HPLC) was also used to measure the exudation of organic acids from Al-stressed root tips. The enzymatic assay revealed some associations between Al tolerance and malate efflux from Al-stressed wheat or triticale roots, although Al-tolerant triticale cvv. Tahara and 19th ITSN 70-4 released less malate than the Al-tolerant wheat. HPLC analysis indicated that malate and citrate were not the main exudates related to the different levels of Al tolerance in these triticale cultivars. A yet to be identified organic acid in 19th ITSN 70-4 showed significant concentration differences from 2 other cultivars tested. This study highlighted the importance and necessity of elucidating the biochemical mechanisms involved in Al stress tolerance in triticale and other crops.


2019 ◽  
Vol 4 (1) ◽  
pp. 16-22
Author(s):  
Robiatul Adawiyah ◽  
Musadia Afa

Aluminum (Al 3+) is rhizotoxic ions in the soil (mineral) acid. Al activities increases with increasing soil acidity, below pH 5.5 the solubility of Al 3+ cations will increase. High level of soluble can cause interference with metabolic processes and plant physiology. Cumulatively, the physiology of metabolic disorders and initially looked at the root system. The tip of the root and lateral roots become thickened and hair and roots become lower, causing a decrease in root length and root tissue enlargement thus inhibiting the growth of roots, the absorption of nutrients and water, will further lower the growth, production and productivity of crops. Although Al disrupt metabolism and suppress the growth of the plant, until a certain threshold of adverse effects in Al still be tolerated, depending on the type of plant and the level of activity of Al. Tolerance of crops to Al can be expressed through two mechanisms, namely: external tolerance mechanism and internal tolerance mechanism. The main difference between the two mechanisms is in the area of detoxification Al whether in symplast (internal) or apoplast (exclusion). The ability of plants to be able to adapt to drought stress Al, depends on the ability of plants to produce organic acid in an amount sufficient for eliminating the toxic influence of stress Al. Root exudates of plants capable of producing such an organic acid that plays an important role in adaptation strategies. The high production of organic acids is associated with the formation of specific enzymes, as a response to stress Al. Allegedly the sensitive strain, the synthesis of organic acids is not adequate to chelate Al


2017 ◽  
Vol 119 ◽  
pp. 265-274 ◽  
Author(s):  
Dongqin Li ◽  
Zaifa Shu ◽  
Xiaoli Ye ◽  
Jiaojiao Zhu ◽  
Junting Pan ◽  
...  

2017 ◽  
Vol 114 (19) ◽  
pp. 5047-5052 ◽  
Author(s):  
Yuqi Wang ◽  
Ruihong Li ◽  
Demou Li ◽  
Xiaomin Jia ◽  
Dangwei Zhou ◽  
...  

Members of the aquaporin (AQP) family have been suggested to transport aluminum (Al) in plants; however, the Al form transported by AQPs and the roles of AQPs in Al tolerance remain elusive. Here we report that NIP1;2, a plasma membrane-localized member of the Arabidopsis nodulin 26-like intrinsic protein (NIP) subfamily of the AQP family, facilitates Al-malate transport from the root cell wall into the root symplasm, with subsequent Al xylem loading and root-to-shoot translocation, which are critical steps in an internal Al tolerance mechanism in Arabidopsis. We found that NIP1;2 transcripts are expressed mainly in the root tips, and that this expression is enhanced by Al but not by other metal stresses. Mutations in NIP1;2 lead to hyperaccumulation of toxic Al3+ in the root cell wall, inhibition of root-to-shoot Al translocation, and a significant reduction in Al tolerance. NIP1;2 facilitates the transport of Al-malate, but not Al3+ ions, in both yeast and Arabidopsis. We demonstrate that the formation of the Al-malate complex in the root tip apoplast is a prerequisite for NIP1;2-mediated Al removal from the root cell wall, and that this requires a functional root malate exudation system mediated by the Al-activated malate transporter, ALMT1. Taken together, these findings reveal a critical linkage between the previously identified Al exclusion mechanism based on root malate release and an internal Al tolerance mechanism identified here through the coordinated function of NIP1;2 and ALMT1, which is required for Al removal from the root cell wall, root-to-shoot Al translocation, and overall Al tolerance in Arabidopsis.


Genome ◽  
1995 ◽  
Vol 38 (6) ◽  
pp. 1213-1220 ◽  
Author(s):  
Daryl J. Somers ◽  
J. Perry Gustafson

This study examined the changes in gene expression induced by aluminum (Al) stress in wheat root tips. Seedlings of Triticum aestivum L. cvs. Katepwa (Al sensitive), Maringa (Al tolerant), and Alikat (Al tolerant near isoline; 'Katepwa'*3/'Maringa') and a F2 population derived from 'Katepwa' × 'Alikat', were grown for 3 days in either 0 or 1 μg∙mL−1 Al. Polypeptides were labeled with 35S-methionine prior to separation by gel electrophoresis. There were a few polypeptides from whole cell lysates that showed enhanced expression in all of the genotypes in 1 μg∙mL−1 Al, however, the whole cell lysate and microsomal polypeptide profiles also revealed numerous unique changes in gene expression in Al-sensitive 'Katepwa' at 1 μg∙mL−1 Al; the latter cosegregated with only the Al-sensitive F2 bulks. The microsomal polypeptide profiles of the Al-tolerant lines 'Maringa' and 'Alikat' changed marginally in the presence of Al and these changes were also reflected in the Al-tolerant F2 bulks. The data showed that there were many changes in gene expression which cosegregated with Al sensitivity and suggest that Al tolerance in wheat may rely on constitutively expressed polypeptides.Key words: wheat, aluminum, protein synthesis, segregation.


1988 ◽  
Vol 66 (4) ◽  
pp. 694-699 ◽  
Author(s):  
Gregory J. Taylor

An aluminum-tolerant cultivar ('Atlas-66') and an aluminum-sensitive cultivar ('Scout-66') of Triticum aestivum L. were grown in solution culture under conditions of varying [Formula: see text] and [Formula: see text] supply with or without 75 μM aluminum. Plants grown with a low [Formula: see text] ratio in solution maintained a higher solution pH than plants grown with a high [Formula: see text] ratio. Although root growth of 'Scout-66' was greater under high [Formula: see text], high solution pH conditions, the relative tolerance of the cultivars to Al was unaffected by the [Formula: see text] ratio and by solution pH. The superior Al tolerance of 'Atlas-66' could not be explained solely by its ability to maintain a high solution pH in mixed nitrogen solutions.


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