Integrative transcriptomic and metabolomic analysis of D-leaf of seven pineapple varieties differing in N-P-K% contents

Jing Chen,Xiumei Zhang,Hui Zeng

doi:10.1186/s12870-021-03291-0

Abstract

BackgroundPineapple (Ananas comosus L. Merr.) is the third most important tropical fruit in China. In other crops, farmers can easily judge the nutritional requirements from leaf color. However, concerning pineapple, it is difficult due to the variation in leaf color of the cultivated pineapple varieties. A detailed understanding of the mechanisms of nutrient transport, accumulation, and assimilation was targeted in this study. We explored the D-leaf nitrogen (N), phosphorus (P), and potassium (K) contents, transcriptome, and metabolome of seven pineapple varieties.ResultsSignificantly higher N, P, and K% contents were observed in Bali, Caine, and Golden pineapple. The transcriptome sequencing of 21 libraries resulted in the identification of 14,310 differentially expressed genes in the D-leaves of seven pineapple varieties. Genes associated with N transport and assimilation in D-leaves of pineapple was possibly regulated by nitrate and ammonium transporters, and glutamate dehydrogenases play roles in N assimilation in arginine biosynthesis pathways. Photosynthesis and photosynthesis-antenna proteins pathways were also significantly regulated between the studied genotypes. Phosphate transporters and mitochondrial phosphate transporters were differentially regulated regarding inorganic P transport. WRKY, MYB, and bHLH transcription factors were possibly regulating the phosphate transporters. The observed varying contents of K% in the D-leaves was associated to the regulation of K+ transporters and channels under the influence of Ca2+ signaling. The UPLC-MS/MS analysis detected 873 metabolites which were mainly classified as flavonoids, lipids, and phenolic acids.ConclusionsThese findings provide a detailed insight into the N, P, K% contents in pineapple D-leaf and their transcriptomic and metabolomic signatures.

Highlights

Variation in D‐leaf N, P, and K contents Phenotypic appearance of the seven pineapple varieties clearly indicates that the leaves differ in their color appearance (Fig. 1a)
Bali (BL) had significantly higher N% among all the seven varieties followed by Golden pineapple (MD2), Tainong-17 (T17), Tainong-4 (T4), Tainong-21 (T21), Tainong-23 (T23), and Caine (CN, known as Smooth Cayene) (Fig. 1b)
Highest and lowest K contents were observed in MD-2 and T4, respectively, while CN, BL, T17, and T21 had no significant differences

Summary

Introduction

Merr.) is the third most important tropical fruit in China. We explored the D-leaf nitrogen (N), phosphorus (P), and potassium (K) contents, transcriptome, and metabolome of seven pineapple varieties. Merr.) is China’s third most important tropical fruit, which is cultivated on about 70,000 hectares. Chen et al BMC Plant Biology (2021) 21:550 fruit quality, yield, and leaf micronutrients content varied with the applied NPK fertilizers [2]. The applied fertilizers can directly influence the nutrient concentrations in D-leaf of pineapple, which have positive influence on the yield and fruit size [3]. The leaf NPK contents directly influence the leaf photosynthetic capacity and affects overall growth and development and reproductive development in pineapple [4, 5]

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Conclusion