Characterization of Purple Acid Phosphatase Family and Functional Analysis of GmPAP7a/7b Involved in Extracellular ATP Utilization in Soybean

Abstract

Low phosphate (Pi) availability limits crop growth and yield in acid soils. Although root-associated acid phosphatases (APases) play an important role in extracellular organic phosphorus (P) utilization, they remain poorly studied in soybean (Glycine max), an important legume crop. In this study, dynamic changes in intracellular (leaf and root) and root-associated APase activities were investigated under both Pi-sufficient and Pi-deficient conditions. Moreover, genome-wide identification of members of the purple acid phosphatase (PAP) family and their expression patterns in response to Pi starvation were analyzed in soybean. The functions of both GmPAP7a and GmPAP7b, whose expression is up regulated by Pi starvation, were subsequently characterized. Phosphate starvation resulted in significant increases in intracellular APase activities in the leaves after 4 days, and in root intracellular and associated APase activities after 1 day, but constant increases were observed only for root intracellular and associated APase activities during day 5-16 of P deficiency in soybean. Moreover, a total of 38 GmPAP members were identified in the soybean genome. The transcripts of 19 GmPAP members in the leaves and 17 in the roots were upregulated at 16 days of P deficiency despite the lack of a response for any GmPAP members to Pi starvation at 2 days. Pi starvation upregulated GmPAP7a and GmPAP7b, and they were subsequently selected for further analysis. Both GmPAP7a and GmPAP7b exhibited relatively high activities against adenosine triphosphate (ATP) in vitro. Furthermore, overexpressing GmPAP7a and GmPAP7b in soybean hairy roots significantly increased root-associated APase activities and thus facilitated extracellular ATP utilization. Taken together, these results suggest that GmPAP7a and GmPAP7b might contribute to root-associated APase activities, thus having a function in extracellular ATP utilization in soybean.

Phosphate (Pi) Starvation Up-Regulated GmCSN5A/B Participates in Anthocyanin Synthesis in Soybean (Glycine max) Dependent on Pi Availability

“…The subcellular localization of GmCSN5A and GmCSN5B was analyzed as previously described [43]. Briefly, the full-length of GmCSN5A and GmCSN5B was separately amplified and cloned into a pEGAD vector with eGFP at its C-terminus.…”

“…The full-length of GmCSN5A and GmCSN5B was separately amplified and cloned into pTF101s vector according to the method described previously [43]. The GmCSN5Aand Gm-CSN5B-pTF101s plasmids were transformed into Arabidopsis by Agrobacterium-mediated transformation as described previously [50].…”

“…However, phosphate starvation restrains soybean growth and yield in soils [39]. To deal with low Pi stress, the soybean has evolved a set of adaptive strategies to enhance Pi mobilization and acquisition in soil, such as the remodeling of root architecture, increased exudation of organic acids and root-associated purple acid phosphatase activities, formation of symbiosis with beneficial microbes (i.e., rhizobia and mycorrhiza fungi) [40][41][42][43]. However, few studies tried to investigate responses of soybean leaves to P deficiency in order to fully understand adaptative strategies of soybean to P deficiency.…”

Genome-Wide Characterization and Evolutionary Analyses of Purple Acid Phosphatase (PAP) Gene Family with Their Expression Profiles in Response to Low Phosphorus Stresses in Moso Bamboo (Phyllostachys edulis)

“…Under normal circumstances, low phosphorus stress can induce the increase in the plant acid phosphatase activity, and acid phosphatase promotes the absorption and utilization of phosphorus by plants [45]; therefore, we measured the activity of acid phosphatase in different organs of Moso bamboo after 0, 48 and 96 h low-phosphorus treatments (Figure 3). The results showed that at 0 h, the acid phosphatase activity in leaves was the highest, followed by stems.…”

Physiological responses and transcriptomic changes reveal the mechanisms underlying adaptation of Stylosanthes guianensis to phosphorus deficiency

“…For example, increase in root length and root/shoot ratio is observed in maize (Zea mays) [11], faba bean (Vicia faba) [12], rapeseed (Brassica napus) and wheat (Triticum aestivum) [13] in response to low P supply. Furthermore, acid phosphatase activities are up-regulated by Pi deprivation in many plants, such as rice (Oryza sativa), soybean (Glycine max) and chickpea (Cicer arietinum), which could contribute to increased organic P utilization [14][15][16].…”