A large-scale screening of quinoa accessions reveals an important role of epidermal bladder cells and stomata! patterning in salinity tolerance
A large-scale screening of quinoa accessions reveals an important role of epidermal bladder cells and stomata! patterning in salinity tolerance
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DOI：
10.1016/j.envexpbot.2019.103885
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发表时间：
2019-12-01
影响因子：
5.7
通讯作者：
Shabala, Sergey
中科院分区：
文献类型：
--
作者：
Kiani-Pouya, Ali;Rasouli, Fatemeh;Shabala, Sergey
在盐植物中的表皮膀胱细胞（EBC）的存在允许在这些外部结构中积累大量的Na+，远离代谢活性的中粒细胞。同样，气孔图案可能代表一种主要机制，植物可以在盐水状态下优化其水利用效率。这项研究的目的是通过评估广泛的加入并将整体盐度耐受性与气孔特征和EBC参数的变化联系起来，探索藜麦（几内亚氏菌）盐度耐受性的品种差异。在温度控制的玻璃室下生长了14个饰品，在非盐水和400毫米NACL条件下生长，并测量了不同的生理和解剖学特征。根据定义为盐度耐受性指数（STI）的相对干重，将加入分为三类（敏感，中间和耐受）。结果表明，STI的差异很大，表明藜麦的盐度耐受性差异很强。在盐水状态下，大多数加入中，膀胱密度增加，而膀胱直径保持不变。这导致膀胱体积作为因变量的差异很大。气孔密度在盐水和非盐度条件之间保持不变，而气孔长度在加入中的3％至43％之间。叶Na+浓度从盐水条件下的669 Mu mol/gdw到3155 Mu mol/gdw，除了一些辅助剂，在盐水条件下，叶子K+浓度增加了。相关分析表明，一方面，EBC直径与STI之间存在显着的正相关，另一方面，EBC的体积和STI在耐盐的组中。这些观察结果与EBC在远离细胞质的外部结构中的隔离Na+中的作用一致。在盐敏感植物中发现EBC密度和直径之间存在负相关。在盐耐盐的基团中也发现了STI和气孔长度之间的负相关性，这表明这些植物能够有效调节气孔模式，以平衡盐分条件下的水损失和CO2同化。在盐水条件下，盐敏感和耐盐的基团在芽中均具有相同的Na+浓度。然而，盐敏感植物中叶Na+浓度与STI之间的负相关性表明，在耐盐植物中，更有效的Na+隔离过程在EBC中更有效。
The presence of epidermal bladder cells (EBCs) in halophytes allows considerable amount of Na+ being accumulated in these external structures, away from the metabolically active mesophile cells. Also, stomatal patterning may represent a primary mechanism by which plants can optimise its water-use efficiency under saline condition. This investigation was aimed to explore the varietal differences in a salinity tolerance of quinoa (Chenopodium guinea) by evaluating a broad range of accessions and linking the overall salinity tolerance with changes in stomatal characteristics and EBC parameters. One hundred and fourteen accessions were grown under temperature-controlled glasshouse under non-saline and 400 mM NaCl conditions, and different physiological and anatomical characteristics were measured. Accessions were classified into three classes (sensitive, intermediate and tolerant) based on a relative dry weight defined as salinity tolerance index (STI). Results showed a large variability in STI indicating a strong genetic variation in salinity tolerance in quinoa. Bladders density was increased in a majority of accessions under saline condition while the bladder's diameter remained unchanged; this resulted in a large variability in a bladder's volume as a dependant variable. Stomata density remained unchanged between saline and non-saline conditions while the stomata length declined between 3% to 43% amongst accessions. Leaf Na+ concentration varied from 669 mu mol/gDW to 3155 mu mol/gDW under saline condition and, with an exception of a few accessions, leaf K+ concentration increased under saline conditions. Correlation analysis indicated a significant positive association between EBC diameter and STI on one hand and EBC volume and STI on the other hand, in a salt-tolerant group. These observations are consistent with the role of EBCs in sequestration of toxic Na+ in the external structures, away from the cytosol. A negative association was found between EBC density and diameter in salt-sensitive plants. A negative association between STI and stomata length was also found in a salt-tolerant group, suggesting that these plants were able to efficiently regulate stomatal patterning to balance water loss and CO2 assimilation under saline conditions. Both salt-sensitive and salt-tolerant groups had the same Na+ concentration in the shoot under saline conditions; however, a negative association between leaf Na+ concentration and STI in salt-sensitive plants indicated a more efficient Na+ sequestration process into the EBCs in salt-tolerant plants.