Tanios S, Thangavel T, Eyles A, Tegg R S, Wilson C R
Tasmanian Institute of Agriculture, University of Tasmania, New Town Research Laboratories, 13 St. Johns Avenue, New Town, Tasmania 7008, Australia.
Photosynthetica. 2025 Feb 13;63(1):37-45. doi: 10.32615/ps.2025.003. eCollection 2025.
Potato tuber greening occurs due to the chlorophyll accumulation upon exposure to light, however, fundamental information on tuber chlorophyll metabolism is lacking. We measured the effect of varying light exposure (0, 48, 96, and 168 h) on chlorophyll concentration and gene expression of enzymes in the chlorophyll metabolic pathway in the potato varieties that differ in greening propensity. Greening was associated with the upregulation of genes involved in chlorophyll biosynthesis, particularly glutamyl-tRNA reductase 1, magnesium-chelatase subunit H, and magnesium-protoporphyrin IX monomethyl ester cyclase, and downregulation of genes involved in chlorophyll cycling and degradation, including chlorophyllide oxygenase, and pheophorbide oxygenase. Our findings suggest that relative resistance to tuber greening propensity may be due to a weaker upregulation of chlorophyll biosynthesis genes and weaker downregulation of chlorophyll degradation genes that occurs in susceptible varieties. The association of these biosynthesis and degradation genes with greening susceptibility may provide possible breeding targets for the future development of more greening-resistant varieties.
马铃薯块茎变绿是由于暴露在光下叶绿素积累所致，然而，关于块茎叶绿素代谢的基础信息却很缺乏。我们测定了不同光照时间（0、48、96和168小时）对不同绿化倾向马铃薯品种叶绿素浓度以及叶绿素代谢途径中酶的基因表达的影响。绿化与叶绿素生物合成相关基因的上调有关，特别是谷氨酰 - tRNA还原酶1、镁螯合酶亚基H和镁原卟啉IX单甲酯环化酶，以及与叶绿素循环和降解相关基因的下调有关，包括叶绿素酸酯加氧酶和脱镁叶绿素加氧酶。我们的研究结果表明，对块茎绿化倾向的相对抗性可能是由于易感品种中叶绿素生物合成基因上调较弱以及叶绿素降解基因下调较弱所致。这些生物合成和降解基因与绿化敏感性的关联可能为未来培育更抗绿化的品种提供潜在的育种目标。
