Quantitative Proteomics Reveals that GmENO2 Proteins Are Involved in Response to Phosphate Starvation in the Leaves of Glycine max L.

Abstract

Soybean (Glycine max L.) is a major crop providing important source for protein and oil for human life. Low phosphate (LP) availability is a critical limiting factor affecting soybean production. Soybean plants develop a series of strategies to adapt to phosphate (Pi) limitation condition. However, the underlying molecular mechanisms responsible for LP stress response remain largely unknown. Here, we performed a label-free quantification (LFQ) analysis of soybean leaves grown under low and high phosphate conditions. We identified 267 induced and 440 reduced differential proteins from phosphate-starved leaves. Almost a quarter of the LP decreased proteins are involved in translation processes, while the LP increased proteins are accumulated in chlorophyll biosynthetic and carbon metabolic processes. Among these induced proteins, an enolase protein, GmENO2a was found to be mostly induced protein. On the transcriptional level, GmENO2a and GmENO2b, but not GmENO2c or GmENO2d, were dramatically induced by phosphate starvation. Among 14 enolase genes, only GmENO2a and GmENO2b genes contain the P1BS motif in their promoter regions. Furthermore, GmENO2b was specifically induced in the GmPHR31 overexpressing soybean plants. Our findings provide molecular insights into how soybean plants tune basic carbon metabolic pathway to adapt to Pi deprivation through the ENO2 enzymes.

Phosphate starvation regulates cellulose synthesis to modify root growth

“…The alteration in translation observed may be due to the reallocation of resources in low Pi conditions, which is in line with previous observations. (Cheng et al ., 2021). However, we found no changes in the abundance of primary wall CESA proteins in response to Pi deficiency (Fig.…”

Proteomic Analysis Dissects Molecular Mechanisms Underlying Plant Responses to Phosphorus Deficiency

“…Moreover, accompanied by changes in shoot morphology, a group of physiological and biochemical processes in response to P deficiency was also influenced. For example, leaf color turned from green to purple or dark-green in most plants under low-P conditions, which was mainly caused by anthocyanin accumulations, along with the reduced chlorophyll contents [ 28 , 29 , 65 ]. Meanwhile, increased starch content and decreased sucrose content in leaves were widely observed in most plants [ 66 , 67 ].…”

“…Reduced accumulations of proteins associated with the photosynthesis process have been observed in plants under P deficiency conditions through differential proteomic analysis, such as proteins related to light energy absorption, electron transfer, and transformation to generate ATP and NADPH. For example, the differential accumulations of a series of proteins were identified, including chlorophyll a/b binding protein in ramie ( Boehmeria nivea ), ferredoxin (Fdx) in soybean, as well as ferredoxin-nitrite reductase (FNR) and alpha/beta subunit of the ATP synthetase in maize ( Figure 1 ) [ 18 , 26 , 28 , 29 ]. Meanwhile, a set of DAPs exhibiting decreased accumulations were found to be involved in rubisco carboxylation reaction (RuBisco), the conversion of ATP and NADPH process, including NADP-malate dehydrogenase (NADP-MDH), pyruvate orthophosphate dikinase (PPDK), phosphoenolpyruvate carboxylase (PEPC), transketolase isoform, RuBisco activase A (RCA), and the large and small subunit of RuBisco [ 18 , 26 , 27 , 40 , 41 ].…”

Mechanisms Underlying Soybean Response to Phosphorus Deficiency through Integration of Omics Analysis

“…Proteomics studies have exponentially increased since "proteome" was first termed in 1994, which developed swiftly from the first to the fourth generation, including gel electrophoresisbased, isotopic labelling-based, shotgun-or label-free-based, and targeted proteomics [45]. With the application of proteomics analysis, differentially accumulated proteins (DAPs) have been identified in different soybean genotypes or organs (e.g., leaves, roots, and nodules) [46][47][48][49][50][51][52][53]. The identification of DAPs sheds light on complicated molecular responses of soybean to Pi deprivation at the translational or post-translational levels.…”

“…Three proteomics studies were conducted in soybean shoots or leaves at different P levels [47,49,51]. Among them, two proteomics analyses were conducted through twodimensional polyacrylamide gel electrophoresis (2-DE), and 37 and 55 DAPs were identified (Table 1) [47,49].…”