Hajjar Ghina, Quellec Stéphane, Challois Sylvain, Bousset-Vaslin Lydia, Joly Gisèle, Langrume Christophe, Deleu Carole, Leport Laurent, Musse Maja
UR OPAALE, INRAE, 17 Avenue de Cucillé, CS 64427, 35044 Rennes, France.
UMR IGEPP, INRAE, Institut Agro-Agrocampus Ouest, Université de Rennes 1, Domaine de la Motte, 35653 Le Rheu, France.
Plants (Basel). 2022 Jul 25;11(15):1918. doi: 10.3390/plants11151918.
The potato is one of the most cultivated crops worldwide, providing an important source of food. The quality of potato tubers relates to their size and dry matter composition and to the absence of physiological defects. It depends on the spatial and temporal coordination of growth and metabolic processes in the major tuber tissues: the cortex, flesh and pith. In the present study, variations in the biochemical traits of each of these tissues were investigated during tuber growth under optimal and water-deficit conditions. MRI relaxometry was used as a non-invasive and quantitative method to access information on cellular water status. The presence of slight but significant variations in organic compound contents quantified in the cortex and flesh revealed a tissue-dependent metabolic pattern. The T and relative I of the bi-exponential relaxation signal allowed a distinction to be made between the pith and the cortex, whereas the flesh could be differentiated from these tissues only through its relative I. T values did not vary significantly during tuber development, in accordance with the typical growth pattern of tubers, but were shown to be sensitive to water stress. The interpretation of the multi-exponential transverse relaxation times is discussed and could be further developed via microscopic analysis.
马铃薯是全球种植最广泛的作物之一，是重要的食物来源。马铃薯块茎的品质与其大小、干物质组成以及是否存在生理缺陷有关。它取决于主要块茎组织（皮层、髓部和髓心）生长与代谢过程的时空协调。在本研究中，研究了在最佳条件和水分亏缺条件下块茎生长过程中这些组织各自生化特性的变化。磁共振成像弛豫测量法被用作一种非侵入性的定量方法，以获取有关细胞水分状态的信息。皮层和髓部中定量的有机化合物含量存在轻微但显著的变化，揭示了一种组织依赖性的代谢模式。双指数弛豫信号的T值和相对I值使髓心和皮层得以区分，而髓部只能通过其相对I值与这些组织区分开来。根据块茎的典型生长模式，T值在块茎发育过程中没有显著变化，但显示出对水分胁迫敏感。文中讨论了多指数横向弛豫时间的解释，并可通过显微镜分析进一步深入研究。
