Departament de Ciències Agràries i del Medi Natural, Universitat Jaume I, 12071, Castelló de la Plana, Spain.
Unitat Predepartamental de Medicina, Universitat Jaume I, 12071, Castelló de la Plana, Spain.
Plant Physiol Biochem. 2018 Jun;127:194-199. doi: 10.1016/j.plaphy.2018.03.029. Epub 2018 Mar 27.
Usually several environmental stresses occur in nature simultaneously causing a unique plant response. However, most of the studies until now have focused in individually-applied abiotic stress conditions. Carrizo citrange (Poncirus trifoliata L. Raf. X Citrus sinensis L. Osb.) and Cleopatra mandarin (Citrus reshni Hort. ex Tan.) are two citrus rootstocks with contrasting tolerance to drought and heat stress and have been used in this work as a model for the study of plant tolerance to the combination of drought and high temperatures. According to our results, leaf integrity and photosynthetic machinery are less affected in Carrizo than in Cleopatra under combined conditions of drought and heat stress. The pattern of accumulation of three proteins (APX, HSP101 and HSP17.6) involved in abiotic stress tolerance shows that they do not accumulate under water stress conditions individually applied. However, contents of APX and HSP101 are higher in Carrizo than in Cleopatra under stress combination whereas HSP17.6 has a similar behavior in both types of plants. This, together with a better stomatal control and a higher APX activity of Carrizo, contributes to the higher tolerance of Carrizo plants to the combination of stresses and point to it as a better rootstock than Cleopatra (traditionally used in areas with scare water supplies) under the predictable future climatic conditions with frequent periods of drought combined with high temperatures. This work also provides the basis for testing the tolerance of different citrus varieties grafted on these rootstocks and growing under different field conditions.
通常，自然界中会同时发生多种环境胁迫，从而导致植物产生独特的响应。然而，直到目前为止，大多数研究都集中在单独应用非生物胁迫条件上。卡里佐甜橙（枳 Poncirus trifoliata L. Raf. × 甜橙 C. sinensis L. Osb.）和克莱门氏小柑橘（克里曼丁橘 C. reshni Hort. ex Tan.）是两种具有不同耐旱耐热性的柑橘砧木，已被用于本研究中，作为研究植物耐受干旱和高温组合胁迫的模型。根据我们的结果，在干旱和高温胁迫的组合条件下，卡里佐的叶片完整性和光合作用机制受影响较小。参与非生物胁迫耐受的三种蛋白质（APX、HSP101 和 HSP17.6）的积累模式表明，它们在单独施加水分胁迫条件下不会积累。然而，在胁迫组合下，APX 和 HSP101 的含量在卡里佐中高于克莱门氏小柑橘，而 HSP17.6 在两种植物中的行为相似。这与卡里佐更好的气孔控制和更高的 APX 活性一起，有助于卡里佐植物对胁迫组合的更高耐受性，并表明它比克莱门氏小柑橘（传统上用于水资源稀缺地区）更适合在未来频繁出现干旱与高温相结合的气候条件下使用。这项工作还为测试不同柑橘品种在这些砧木上的嫁接耐受性以及在不同田间条件下的生长提供了基础。
