Expression of a phosphate-starvation inducible fructose-1,6-bisphosphatase gene in common bean nodules correlates with phosphorus use efficiency

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• 作者：Mohamed Lazali^a ; ^b ; ^{m.lazali@yahoo.fr" class="auth_mail" title="E-mail the corresponding author} (Dr.) ; Adnane Bargaz^c ; Samira Brahimi^a ; Laurie Amenc^b ; Josiane Abadie^b ; Jean Jacques Drevon^b
• 关键词：APase ; acide phosphatase ; CIAT ; International Center of Tropical Agriculture ; DAT ; days after transplantation ; DW ; dry weight ; EURS ; efficiency in use of the rhizobial symbiosis ; FBPase ; fructose-1 ; 6-bisphosphatase ; FW ; fresh weight ; P ; phosphorus ; PUE ; phosphorus use efficiency ; RIL ; recombinant inbred line ; SNF ; symbiotic nitrogen fixation
• 刊名：Journal of Plant Physiology
• 出版年：2016
• 出版时间：20 October 2016
• 年：2016
• 卷：205
• 期：Complete
• 页码：48-56
• 全文大小：2784 K

文摘

While increased P-hydrolysing acid phosphatases (APase) activity in bean nodules is well documented under phosphorus (P) limitation, gene expression and subcellular localization patterns within the N₂-fixing nodule tissues are poorly understood. The aim of this research was to track the enzyme activity along with the intra-nodular localization of fructose-1,6-bisphosphatase (FBPase), and its contribution to P use efficiency (PUE) under symbiotic nitrogen fixation (SNF) in Phaseolus vulgaris. The FBPase transcript were localized in situ using RT-PCR and the protein activity was measured in nodules of two contrasting recombinant inbred lines (RILs) of P. vulgaris, namely RILs 115 (P-efficient) and 147 (P-inefficient), that were grown under sufficient versus deficient P supply. Under P-deficiency, higher FBPase transcript fluorescence was found in the inner cortex as compared to the infected zone of RIL115. In addition, both the specific FBPase and total APase enzyme activities significantly increased in both RILs, but to a more significant extent in RIL115 as compared to RIL147. Furthermore, the increased FBPase activity in nodules of RIL115 positively correlated with higher use efficiency of both the rhizobial symbiosis (23%) and P for SNF (14% calculated as the ratio of N₂ fixed per nodule total P content). It is concluded that the abundant tissue-specific localized FBPase transcript along with induced enzymatic activity provides evidence of a specific tolerance mechanism where N₂-fixing nodules overexpress under P-deficiency conditions. Such a mechanism would maximise the intra-nodular inorganic P fraction necessary to compensate for large amount of P needed during the SNF process.