Shao Yuhang, Cheng Yukun, Pang Hongguang, Chang Mingqin, He Fang, Wang Minmin, Davis Destiny J, Zhang Shuxiao, Betz Oliver, Fleck Chuck, Dai Tingbo, Madahhosseini Shahab, Wilkop Thomas, Jernstedt Judy, Drakakaki Georgia
Department of Plant Sciences, University of California, Davis, Davis, CA, United States.
Key Laboratory of Crop Physiology Ecology and Production Management of Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China.
Front Plant Sci. 2021 Jan 5;11:595055. doi: 10.3389/fpls.2020.595055. eCollection 2020.
The intensive use of groundwater in agriculture under the current climate conditions leads to acceleration of soil salinization. Given that almond is a salt-sensitive crop, selection of salt-tolerant rootstocks can help maintain productivity under salinity stress. Selection for tolerant rootstocks at an early growth stage can reduce the investment of time and resources. However, salinity-sensitive markers and salinity tolerance mechanisms of almond species to assist this selection process are largely unknown. We established a microscopy-based approach to investigate mechanisms of stress tolerance in and identified cellular, root anatomical, and molecular traits associated with rootstocks exhibiting salt tolerance. We characterized three almond rootstocks: Empyrean-1 (E1), Controller-5 (C5), and Krymsk-86 (K86). Based on cellular and molecular evidence, our results show that E1 has a higher capacity for salt exclusion by a combination of upregulating ion transporter expression and enhanced deposition of suberin and lignin in the root apoplastic barriers, exodermis, and endodermis, in response to salt stress. Expression analyses revealed differential regulation of cation transporters, stress signaling, and biopolymer synthesis genes in the different rootstocks. This foundational study reveals the mechanisms of salinity tolerance in almond rootstocks from cellular and structural perspectives across a root developmental gradient and provides insights for future screens targeting stress response.
在当前气候条件下，农业中对地下水的大量使用导致土壤盐渍化加速。鉴于杏仁是一种对盐敏感的作物，选择耐盐砧木有助于在盐分胁迫下维持产量。在早期生长阶段选择耐盐砧木可以减少时间和资源的投入。然而，用于辅助这一选择过程的杏仁品种的盐分敏感标记和耐盐机制在很大程度上尚不清楚。我们建立了一种基于显微镜的方法来研究耐胁迫机制，并确定了与表现出耐盐性的砧木相关的细胞、根解剖和分子特征。我们对三种杏仁砧木进行了表征：Empyrean - 1（E1）、Controller - 5（C5）和Krymsk - 86（K86）。基于细胞和分子证据，我们的结果表明，E1通过上调离子转运蛋白表达以及增强根外质体屏障、外皮层和内皮层中木栓质和木质素的沉积，对盐胁迫作出反应，具有更高的排盐能力。表达分析揭示了不同砧木中阳离子转运蛋白、胁迫信号和生物聚合物合成基因的差异调控。这项基础研究从细胞和结构角度揭示了杏仁砧木在整个根发育梯度上的耐盐机制，并为未来针对胁迫反应的筛选提供了见解。
