Linking salinity stress tolerance with tissue-specific Na+ sequestration in wheat roots
Salinity stress tolerance is a physiologically complex trait that is conferred by the large array of interacting mechanisms. Among these, vacuolar Na+ sequestration has always been considered as one of the key components differentiating between sensitive and tolerant species and genotypes. However,...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2015-02-01
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| Series: | Frontiers in Plant Science |
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| Online Access: | http://journal.frontiersin.org/Journal/10.3389/fpls.2015.00071/full |
| _version_ | 1818561334106652672 |
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| author | Honghong eWu Lana eShabala Xiaohui eLiu Elisa eAzzarello Camilla ePandolfi Meixue eZhou Zhong-Hua eChen Jayakumar eBose Stefano eMancuso Sergey eShabala |
| author_facet | Honghong eWu Lana eShabala Xiaohui eLiu Elisa eAzzarello Camilla ePandolfi Meixue eZhou Zhong-Hua eChen Jayakumar eBose Stefano eMancuso Sergey eShabala |
| author_sort | Honghong eWu |
| collection | DOAJ |
| description | Salinity stress tolerance is a physiologically complex trait that is conferred by the large array of interacting mechanisms. Among these, vacuolar Na+ sequestration has always been considered as one of the key components differentiating between sensitive and tolerant species and genotypes. However, vacuolar Na+ sequestration has been rarely considered in the context of the tissue-specific expression and regulation of appropriate transporters contributing to Na+ removal from the cytosol. In this work, six bread wheat varieties contrasting in their salinity tolerance (three tolerant and three sensitive) were used to understand the essentiality of vacuolar Na+ sequestration between functionally different root tissues, and link it with the overall salinity stress tolerance in this species. Roots of 4-d old wheat seedlings were treated with 100 mM NaCl for 3 days, and then Na+ distribution between cytosol and vacuole was quantified by CoroNa Green fluorescent dye imaging. Our major observations were as follows: 1) salinity stress tolerance correlated positively with vacuolar Na+ sequestration ability in the mature root zone but not in the root apex; 2) Contrary to expectations, cytosolic Na+ levels in root meristem were significantly higher in salt tolerant than sensitive group, while vacuolar Na+ levels showed an opposite trend. These results are interpreted as meristem cells playing a role of the salt sensor; 3) No significant difference in the vacuolar Na+ sequestration ability was found between sensitive and tolerant group in either transition or elongation zones; 4) The overall Na+ accumulation was highest in the elongation zone, suggesting its role in osmotic adjustment and turgor maintenance required to drive root expansion growth. Overall, the reported results suggest high tissue-specificity of Na+ uptake, signalling, and sequestration in wheat root. The implications of these findings for plant breeding for salinity stress tolerance are discussed. |
| first_indexed | 2024-12-14T00:49:29Z |
| format | Article |
| id | doaj.art-559013c6789742a79e3dd5dea5657970 |
| institution | Directory Open Access Journal |
| issn | 1664-462X |
| language | English |
| last_indexed | 2024-12-14T00:49:29Z |
| publishDate | 2015-02-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Plant Science |
| spelling | doaj.art-559013c6789742a79e3dd5dea56579702022-12-21T23:23:55ZengFrontiers Media S.A.Frontiers in Plant Science1664-462X2015-02-01610.3389/fpls.2015.00071107903Linking salinity stress tolerance with tissue-specific Na+ sequestration in wheat rootsHonghong eWu0Lana eShabala1Xiaohui eLiu2Elisa eAzzarello3Camilla ePandolfi4Meixue eZhou5Zhong-Hua eChen6Jayakumar eBose7Stefano eMancuso8Sergey eShabala9University of TasmaniaUniversity of TasmaniaUniversity of Western SydneyUniversity of FlorenceUniversity of FlorenceUniversity of TasmaniaUniversity of Western SydneyUniversity of TasmaniaUniversity of FlorenceUniversity of TasmaniaSalinity stress tolerance is a physiologically complex trait that is conferred by the large array of interacting mechanisms. Among these, vacuolar Na+ sequestration has always been considered as one of the key components differentiating between sensitive and tolerant species and genotypes. However, vacuolar Na+ sequestration has been rarely considered in the context of the tissue-specific expression and regulation of appropriate transporters contributing to Na+ removal from the cytosol. In this work, six bread wheat varieties contrasting in their salinity tolerance (three tolerant and three sensitive) were used to understand the essentiality of vacuolar Na+ sequestration between functionally different root tissues, and link it with the overall salinity stress tolerance in this species. Roots of 4-d old wheat seedlings were treated with 100 mM NaCl for 3 days, and then Na+ distribution between cytosol and vacuole was quantified by CoroNa Green fluorescent dye imaging. Our major observations were as follows: 1) salinity stress tolerance correlated positively with vacuolar Na+ sequestration ability in the mature root zone but not in the root apex; 2) Contrary to expectations, cytosolic Na+ levels in root meristem were significantly higher in salt tolerant than sensitive group, while vacuolar Na+ levels showed an opposite trend. These results are interpreted as meristem cells playing a role of the salt sensor; 3) No significant difference in the vacuolar Na+ sequestration ability was found between sensitive and tolerant group in either transition or elongation zones; 4) The overall Na+ accumulation was highest in the elongation zone, suggesting its role in osmotic adjustment and turgor maintenance required to drive root expansion growth. Overall, the reported results suggest high tissue-specificity of Na+ uptake, signalling, and sequestration in wheat root. The implications of these findings for plant breeding for salinity stress tolerance are discussed.http://journal.frontiersin.org/Journal/10.3389/fpls.2015.00071/fullbread wheatcytosolic Na+Na+ distributionroot zonessalinity stress tolerancevacuolar Na+ sequestration |
| spellingShingle | Honghong eWu Lana eShabala Xiaohui eLiu Elisa eAzzarello Camilla ePandolfi Meixue eZhou Zhong-Hua eChen Jayakumar eBose Stefano eMancuso Sergey eShabala Linking salinity stress tolerance with tissue-specific Na+ sequestration in wheat roots Frontiers in Plant Science bread wheat cytosolic Na+ Na+ distribution root zones salinity stress tolerance vacuolar Na+ sequestration |
| title | Linking salinity stress tolerance with tissue-specific Na+ sequestration in wheat roots |
| title_full | Linking salinity stress tolerance with tissue-specific Na+ sequestration in wheat roots |
| title_fullStr | Linking salinity stress tolerance with tissue-specific Na+ sequestration in wheat roots |
| title_full_unstemmed | Linking salinity stress tolerance with tissue-specific Na+ sequestration in wheat roots |
| title_short | Linking salinity stress tolerance with tissue-specific Na+ sequestration in wheat roots |
| title_sort | linking salinity stress tolerance with tissue specific na sequestration in wheat roots |
| topic | bread wheat cytosolic Na+ Na+ distribution root zones salinity stress tolerance vacuolar Na+ sequestration |
| url | http://journal.frontiersin.org/Journal/10.3389/fpls.2015.00071/full |
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