Key Laboratory of Forest Tree Genetics, Breeding and Cultivation of Liaoning Province, College of Forestry, Shenyang Agricultural University, Shenyang, 110866, Liaoning, China.
Mol Biol Rep. 2022 Mar;49(3):1925-1934. doi: 10.1007/s11033-021-07004-6. Epub 2021 Dec 3.
Lycium ruthenicum is an eco-economic shrub which can exist in two forms, thorny and thornless under varying soil moisture conditions. The aim of this study was to determine if the two forms of L. ruthenicum were influenced by soil water content (SWC) and to test the three-way link among SWC, occurrence of branch-thorn and DNA methylation modification.
Here, pot experiment was carried out to reveal the influence of SWC on the occurrence of branch-thorn and then paraffin sections, scanning electron microscope and methylation-sensitive amplification polymorphism(MSAP) analysis were used to determine the three-way link among SWC, branch-thorn occurrence and DNA methylation. The results showed that (a) soil drought promoted the development of thorn primordium into branch-thorn and (b) branch-thorn covered axillary bud to protect it against drought and other stresses; (c) the branch-thorn occurrence response to drought was correlated with hypermethylation of CCGG sites and (d) thorny and thornless plants of a clone were distinguished successfully based on the MSAP profiles of their leaves.
Branch-thorns of the L. ruthenicum clone, which occurred in response to drought, covered axillary buds to protect them against drought and other stresses; thorn primordium of the clone did not develop into branch-thorn under the adequate soil moisture condition. The occurrence and absence of the branch-thorns were correlated with the hyper- and hypo-methylation, respectively. We proposed that the branch-thorn plasticity might be an adjustment strategy for the environment, which seems to support the theory of "Use in, waste out".
枸杞是一种生态经济型灌木，在不同的土壤水分条件下可以存在有刺和无刺两种形式。本研究旨在确定枸杞的两种形式是否受土壤水分含量（SWC）的影响，并检验 SWC、分枝叶发生和 DNA 甲基化修饰之间的三向联系。
本研究通过盆栽实验揭示了 SWC 对分枝叶发生的影响，然后使用石蜡切片、扫描电子显微镜和甲基化敏感扩增多态性（MSAP）分析来确定 SWC、分枝叶发生和 DNA 甲基化之间的三向联系。结果表明：（a）土壤干旱促进了刺原基发育成分枝叶；（b）分枝叶覆盖腋芽以保护其免受干旱和其他胁迫；（c）分枝叶对干旱的响应与 CCGG 位点的超甲基化有关；（d）基于叶片的 MSAP 图谱，可以成功区分克隆的有刺和无刺植物。
克隆的枸杞分枝叶在响应干旱时发生，覆盖腋芽以保护其免受干旱和其他胁迫；在充足的土壤水分条件下，克隆的刺原基不会发育成分枝叶。分枝叶的发生和缺失分别与超甲基化和低甲基化有关。我们提出，分枝叶的可塑性可能是一种适应环境的策略，这似乎支持了“用进废退”的理论。
