Bonnin Marie, Favreau Bénédicte, Soriano Alexandre, Leonhardt Nathalie, Oustric Julie, Lourkisti Radia, Ollitrault Patrick, Morillon Raphaël, Berti Liliane, Santini Jérémie
CNRS, Equipe d'Adaptation des Végétaux Aux Changements Globaux, Projet Ressources Naturelles, UMR 6134 SPE, Universite de Corse, Corte, 20250 Corsica, France.
Unité Mixte de Recherche Amélioration Génétique et Adaptation des Plantes Méditerranéennes et Tropicales (UMR AGAP) Institut, Centre de Coopération Internationale en Recherche Agronomique Pour le Développement (CIRAD), av Agropolis, 34000 Montpellier, France.
Antioxidants (Basel). 2023 Aug 19;12(8):1640. doi: 10.3390/antiox12081640.
Citrus are classified as salt-sensitive crops. However, a large diversity has been observed regarding the trends of tolerance among citrus. In the present article, physiological and biochemical studies of salt stress tolerance were carried out according to the level of polyploidy of different citrus genotypes. We particularly investigated the impact of tetraploidy in trifoliate orange ( (L.) Raf.) (PO4x) and Cleopatra mandarin ( Hort. Ex Tan.) (CL4x) on the tolerance to salt stress compared to their respective diploids (PO2x and CL2x). Physiological parameters such as gas exchange, ions contents in leaves and roots were analyzed. Roots and leaves samples were collected to measure polyphenol, malondialdehyde (MDA), ascorbate and HO contents but also to measure the activities of enzymes involved in the detoxification of active oxygen species (ROS). Under control conditions, the interaction between genotype and ploidy allowed to discriminate different behavior in terms of photosynthetic and antioxidant capacities. These results were significantly altered when salt stress was applied when salt stress was applied. Contrary to the most sensitive genotype, that is to say the diploid trifoliate orange PO2x, PO4x was able to maintain photosynthetic activity under salt stress and had better antioxidant capacities. The same observation was made regarding the CL4x genotype known to be more tolerant to salt stress. Our results showed that tetraploidy may be a factor that could enhance salt stress tolerance in citrus.
柑橘被归类为对盐敏感的作物。然而，在柑橘的耐盐性趋势方面已观察到很大的差异。在本文中，根据不同柑橘基因型的多倍体水平进行了盐胁迫耐受性的生理生化研究。我们特别研究了与各自的二倍体（枳（Poncirus trifoliata (L.) Raf.）（PO2x）和埃及酸橙（Citrus reshni Hort. Ex Tan.）（CL2x）相比），枳四倍体（PO4x）和埃及酸橙四倍体（CL4x）对盐胁迫耐受性的影响。分析了气体交换、叶片和根系中的离子含量等生理参数。采集根和叶样本以测量多酚、丙二醛（MDA）、抗坏血酸和过氧化氢（H₂O₂）含量，还测量了参与活性氧（ROS）解毒的酶的活性。在对照条件下，基因型和倍性之间的相互作用使得能够在光合和抗氧化能力方面区分不同的表现。当施加盐胁迫时这些结果发生了显著变化。与最敏感的基因型即二倍体枳PO2x相反，PO4x在盐胁迫下能够维持光合活性并具有更好的抗氧化能力。对于已知更耐盐胁迫的CL4x基因型也有相同的观察结果。我们的结果表明，四倍体可能是增强柑橘盐胁迫耐受性的一个因素。
