蔗糖通过能量和信号双重作用促进黑果枸杞枝刺发生

Lycium ruthenicum is an important eco-economic thorny shrub.In this study,L.ruthenicum plants of a clone showed two types of'less leaves without thorn'and'more leaves with thorns'under the same condition after transplanting.Morphological differences of organisms usually lag behind the related gene expression and physiological differences.Thus,to excavate the key genes involved in the occurrence of visible thorns of L.ruthenicum,the materials before the first thorn primordium should be selected for comparison.RNA-Seq analysis showed that KEGG pathway of Starch and sucrose metabolism and DEGs of SUT13,SUS,TPP and TPS were significantly up-regulated in the Thorny.The COG Function Class with the largest number of DEGs between the Thless and Thorny was Carbohydrate transport and metabolism.The content of sucrose in the Thorny was significantly higher than that in the Thless,but the content of trehalose-6-phosphate was opposite.Leaf-clipping treatments reduced sucrose content and inhibited the occurrence/development of branch-thorns;exogenous sucrose of 16g/L significantly promoted the occurrence and growth of branch-thorns and the promotion effects were significantly higher than those treated with non-metabolizable sucrose analogs.These findings suggested that sucrose might play a dual role of energy and signal in the occurrence of branch-thorns.Higher sucrose supply in apical buds from more leaves promoted the occurrence of branch-thorns via lower content of trehalose-6-phosphate and higher expression levels of SUS,TPP and TPS,whereas less leaves inhibited the occurrence.Molecular hypothesis model of leaf number/sucrose supply regulating the occurrence of branch-thorns in L.ruthenicum was established in the study,which provides foundation for breeding both thornless L.ruthenicum and thornless types of other species.