Raspor Martin, Mrvaljević Miloš, Savić Jelena, Ćosić Tatjana, Kaleri Abdul Rasheed, Pokimica Nina, Cingel Aleksandar, Ghalawnji Nabil, Motyka Václav, Ninković Slavica
Department of Plant Physiology, Institute for Biological Research "Siniša Stanković" - National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia.
School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, China.
Front Plant Sci. 2024 Feb 1;14:1296520. doi: 10.3389/fpls.2023.1296520. eCollection 2023.
Cytokinin (CK) is a plant hormone that plays crucial roles in regulating plant growth and development. CK-deficient plants are widely used as model systems for investigating the numerous physiological roles of CK. Since it was previously shown that transgenic or mutant CK-deficient and plants show superior tolerance to salinity, we examined the tolerance of three CK-deficient potato lines overexpressing the () gene to 50 mM, 100 mM, 150 mM, and 200 mM NaCl applied . Quantification of visible salinity injury, rooting and acclimatization efficiency, shoot growth, water saturation deficit, and chlorophyll content confirmed that the CK-deficient potato plants were more tolerant to low (50 mM) and moderate (100 mM) NaCl concentrations, but exhibited increased sensitivity to severe salinity stress (150 and 200 mM NaCl) compared to non-transformed control plants. These findings were corroborated by the data distribution patterns according to principal component analysis. Quantification of the activity of superoxide dismutases, peroxidases, and catalases revealed an impaired ability of -transgenic lines to upregulate the activity of antioxidant enzymes in response to salinity, which might contribute to the enhanced sensitivity of these potato lines to severe salt stress. Our results add complexity to the existing knowledge on the regulation of salinity tolerance by CK, as we show for the first time that CK-deficient plants can exhibit reduced rather than increased tolerance to severe salt stress.
细胞分裂素（CK）是一种植物激素，在调节植物生长发育中发挥着关键作用。CK缺陷型植物被广泛用作研究CK众多生理作用的模型系统。由于先前已表明转基因或突变的CK缺陷型植物对盐胁迫具有更高的耐受性，我们检测了过表达（）基因的三个CK缺陷型马铃薯品系对施加的50 mM、100 mM、150 mM和200 mM NaCl的耐受性。对可见盐害、生根和驯化效率、地上部生长、水分饱和亏缺和叶绿素含量的量化结果证实，与未转化的对照植株相比，CK缺陷型马铃薯植株对低浓度（50 mM）和中等浓度（100 mM）的NaCl更具耐受性，但对严重盐胁迫（150 mM和200 mM NaCl）表现出更高的敏感性。主成分分析的数据分布模式证实了这些发现。对超氧化物歧化酶、过氧化物酶和过氧化氢酶活性的量化结果显示，转基因品系响应盐胁迫上调抗氧化酶活性的能力受损，这可能导致这些马铃薯品系对严重盐胁迫的敏感性增强。我们的结果为现有关于CK调节盐耐受性的知识增添了复杂性，因为我们首次表明CK缺陷型植物对严重盐胁迫的耐受性可能降低而非增强。
