Phosphate Treatment Strongly Inhibits New Arbuscule Development But Not the Maintenance of Arbuscule in Mycorrhizal Rice Roots. Issue 1 (15th March 2016)

• Record Type: Journal Article
• Authors: Kobae, Yoshihiro; Ohmori, Yoshihiro; Saito, Chieko; Yano, Koji; Ohtomo, Ryo; Fujiwara, Toru
• Is Part Of: Plant physiology. Volume 171:Issue 1(2016)
• Page Start: 566
• Page End: 579
• Publication Date: 2016-03-15
• Subjects: Plant physiology -- Periodicals; Botany -- Periodicals; Periodicals; Electronic journals; 571.2
• DOI: 10.1104/pp.16.00127
• Languages: English
• ISSNs: 0032-0889

Abstract

Abstract : Intracellular colonization of arbuscular mycorrhizal fungi is rapidly and temporarily inhibited by P and is stabilized by plant symbiotic P transporter. Abstract: Phosphorus (P) is a crucial nutrient for plant growth, but its availability to roots is limited in soil. Arbuscular mycorrhizal (AM ) symbiosis is a promising strategy for improving plant P acquisition. However, P fertilizer reduces fungal colonization (P inhibition) and compromises mycorrhizal P uptake, warranting studies on the mechanistic basis of P inhibition. In this study, early morphological changes in P inhibition were identified in rice ( Oryza sativa ) using fungal cell wall staining and live-cell imaging of plant membranes that were associated with arbuscule life cycles. Arbuscule density decreased, and aberrant hyphal branching was observed in roots at 5 h after P treatment. Although new arbuscule development was severely inhibited, preformed arbuscules remained intact and longevity remained constant. P inhibition was accelerated in the rice pt11-1 mutant, which lacks P uptake from arbuscule branches, suggesting that mature arbuscules are stabilized by the symbiotic P transporter under high P condition. Moreover, P treatment led to increases in the number of vesicles, in which lipid droplets accumulated and then decreased within a few days. The development of new arbuscules resumed within by 2 d. Our data established that P strongly and temporarily inhibits new arbuscule development, but not intraradical accommodation of AM fungi.