Jedynak Pawel, Trzebuniak Kamil Filip, Chowaniec Magdalena, Zgłobicki Piotr, Banaś Agnieszka Katarzyna, Mysliwa-Kurdziel Beata
Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland.
Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland.
Front Plant Sci. 2022 Feb 22;12:772727. doi: 10.3389/fpls.2021.772727. eCollection 2021.
Although etiolated seedlings are widely used as a model to study the de-etiolation process, the etiolation itself at the molecular level still needs elucidation. Here, we monitored the etiolation dynamics for wild type seedlings and lutein-deficient () mutant between 2 and 12 days of their growth in the absence of light. We analyzed the shape of the apex, the growth rate, the carotenoids and protochlorophyllide (Pchlide) accumulation, and the light-dependent protochlorophyllide oxidoreductase () transcripts. Differences concerning the apical hook curvature and cotyledon opening among seedlings of the same age were observed, mostly after day 6 of the culture. We categorized the observed apex shapes and presented quantitatively how distribution among the categories changed during 12 days of seedling growth. The Pchlide/Pchlide ratio, corresponding to the amount of the photoactive Pchlide, was the highest in the youngest seedlings, and decreased with their age. , , and transcripts were detected in etiolated seedlings, and their content decreased during seedling growth. Expression of or senescence markers, depletion in antioxidants, and excess ion leakage were not observed during the etiolation. Lack of lutein in the mutant resulted in slow Pchlide accumulation and affected other xanthophyll composition.
尽管黄化幼苗被广泛用作研究脱黄化过程的模型，但黄化现象本身在分子水平上仍有待阐明。在此，我们监测了野生型幼苗和叶黄素缺陷型（）突变体在无光条件下生长2至12天期间的黄化动态。我们分析了顶端形状、生长速率、类胡萝卜素和原叶绿素酸酯（Pchlide）的积累以及光依赖性原叶绿素酸酯氧化还原酶（）转录本。在相同年龄的幼苗中观察到了顶端弯钩曲率和子叶张开方面的差异，大多在培养6天后出现。我们对观察到的顶端形状进行了分类，并定量呈现了在幼苗生长12天期间各类别之间的分布变化情况。与光活性Pchlide量相对应的Pchlide/Pchlide比值在最年幼的幼苗中最高，并随着幼苗年龄的增长而降低。在黄化幼苗中检测到了、和转录本，且它们的含量在幼苗生长过程中下降。在黄化过程中未观察到或衰老标记物的表达、抗氧化剂的消耗以及过量离子泄漏。突变体中缺乏叶黄素导致Pchlide积累缓慢，并影响了其他叶黄素成分。
