Study on high temperature tolerance of Citrus maxima ‘Mansailong’ seeds at different development stages

Subjects: Biology >> Botany >> Applied botany submitted time 2023-12-24 Cooperative journals: 《广西植物》

AN Xuejiao YANG Lan WEN Bin CHEN Ligang

Abstract： The seeds are invariably exposed to high temperature conditions since global warming frequently causes abnormally high temperatures. This study used intermediate Citrus maxima ‘Mansailong’ seeds as the research material, heated the seeds at different developmental stages, and simultaneously detected changes in seed morphology, contents of soluble and heat-stable proteins, and cellular ultrastructure in order to investigate the physiological basis of high-temperature tolerance in seeds. The results were as follows: (1) The seed moisture content dramatically dropped between 23 and 49 WAF (weeks after flowering), whereas the percentage of DW/FW and fresh weight increased significantly. All of these indicators began to change quickly from 31 WAF and stabilized around 41 WAF. (2) At 29 WAF, the seeds acquired full seedling formation ability and a preliminary tolerance to high temperatures; from there, the high-temperature tolerance gradually grew and improved quickly between 37 and 49 WAF. The improvement in high-temperature tolerance was accompanied by a steady increase in the contents of soluble and heat-stable protein in seeds, from 23 to 49 WAF. The results of the correlation analysis showed a substantial positive correlation between the accumulation of heat-stable and soluble proteins and the ability of seeds to tolerate high temperatures. (3) Ultrastructural observation showed that the number of mitochondria progressively dropped as the seed developed, the volume of the embryonic axis cells gradually decreased, and the number of lipid bodies in the cells gradually rose and their arrangement became more and more regular. In addition, the vacuoles enlarge at the same time, and at a later stage, they were packed with black floccules. In conclusion, the Citrus maxima ‘Mansailong’ seeds reached physiological maturity at 41 WAF without any noticeable maturation drying; the ability to withstand high temperatures was acquired during seed development and was further enhanced until a later stage; changes in cellural ultrastructure and an increase in soluble and heat-stable protein contents of the seeds were essential in helping the seeds develop their high-temperature tolerance.

 Hits 546  Downloads 121  Comment 0