Key Laboratory of Forest Tree Genetics, Breeding and Cultivation of Liaoning Province, College of Forestry, Shenyang Agricultural University, Shenyang 110866, China.
Tree Physiol. 2022 Sep 8;42(9):1841-1857. doi: 10.1093/treephys/tpac047.
Micropropagation is very important for rapid clonal propagation and scientific research of woody plants. However, the micropropagated materials usually show hyperhydricity, which seriously hinders application of the micropropagation. Lycium ruthenicum is an important species of eco-economic forests. Herein, treatment of 'starvation and drying combined with 30 μM AgNO3' (SDCAg+) removed serious hyperhydricity of L. ruthenicum buds regenerated from its green-inflorescence-explants, and then gene expression, metabolites of various phytohormones, chloroplasts, chlorophyll (Chl) and total soluble proteins of the hyperhydric and dehyperhydric leaves were compared and analyzed. The results suggested that the SDCAg+ treatment might remove hyperhydricity of L. ruthenicum through: reducing water uptake; increasing water loss; up-regulating the expression of chloroplast-ribosomal-protein genes from nuclear genome; down-regulating the expression of cytoplasmic-ribosomal-protein genes; up-regulating the synthesis of the total soluble proteins; restoring the lamellar structure of chloroplast grana and matrix; improving Chl synthesis and reducing Chl metabolism; increasing expression of light-harvesting Chl protein complex genes and content of Chla and b; up-regulating both photosynthesis and starch and sucrose metabolism KEGG pathways; up-regulating abscisic acid, salicylic acid and their signaling; down-regulating cytokinin, jasmonic acid, jasmonoyl-l-isoleucine and their signaling. Also, the above events interact to form a regulatory network of dehyperhydricity by SDCAg+ treatment. Overall, the study indicated key genes/pathways and physiological/subcellular changes involved in dehyperhydricity and then established a dehyperhydric mechanism model of L. ruthenicum. This not only proposed clues for preventing or removing hyperhydricity but also laid foundations for molecular breeding of L. ruthenicum and other species.
微繁殖对于木本植物的快速无性繁殖和科学研究非常重要。然而，微繁殖的材料通常表现出过度水化，严重阻碍了微繁殖的应用。黑果枸杞是生态经济林的重要物种。在此，通过“饥饿和干燥结合 30 μM AgNO3（SDCAg+）”处理，可以去除黑果枸杞绿花序外植体再生芽的严重过度水化，并比较和分析了过度水化和去水化叶片的基因表达、各种植物激素、叶绿体、叶绿素（Chl）和总可溶性蛋白的代谢物。结果表明，SDCAg+处理可能通过以下方式去除黑果枸杞的过度水化：减少水分吸收；增加水分损失；上调核基因组叶绿体核糖体蛋白基因的表达；下调细胞质核糖体蛋白基因的表达；上调总可溶性蛋白的合成；恢复叶绿体基粒和基质的层状结构；改善 Chl 合成并减少 Chl 代谢；增加光捕获 Chl 蛋白复合物基因的表达和 Chla 和 b 的含量；上调光合作用和淀粉及蔗糖代谢 KEGG 途径；上调脱落酸、水杨酸及其信号；下调细胞分裂素、茉莉酸、茉莉酸异亮氨酸及其信号。此外，上述事件相互作用，形成了 SDCAg+处理去水化的调控网络。总的来说，该研究表明了参与去水化的关键基因/途径和生理/亚细胞变化，然后建立了黑果枸杞去水化的机制模型。这不仅为防止或去除过度水化提供了线索，也为黑果枸杞和其他物种的分子育种奠定了基础。
