Introduction

Peanuts (Arachis hypogaea) are an important source of protein, oil, and other nutrients, making them a popular food crop around the world. They are used in a variety of food products, including peanut butter, roasted peanuts, and peanut oil. The by-products of peanut processing, such as peanut meal and peanut hulls, are used as animal feed. Overall, the economic value of Arachis hypogaea is significant, with the global peanut market estimated to be worth billions of dollars.

Peanuts, belong to the Dalbergioid clade, which displays diverse and unusual developmental features. Peanut is a classic example of a plant that exhibits geocarpy, which is also known as hypogeous fruiting. After pollination, the peanut plant forms a structure called a peg, which is a modified stem that grows down into the soil. The peg then elongates and eventually forms a pod underground, where the seeds develop. Once the seeds are mature, the pod splits open, and the seeds are dispersed. Peanut also forms atypical nodules, where bacteria enter the plant through developmental fissures called "crack invasion," resulting in uniformly infected nodules. Arachis sp. exhibits an uncommon nodule developmental program characterized by a combination of ancient and advanced features, such as "crack entry," "bacteroid terminal differentiation," and also possesses high nitrogen fixation efficiency.

About AhNGE

Here we have compiled available RNAseq data from Peanut transcriptome analysis. This database contains publicly available RNAseq data that were analyzed against the Tifrunner genome v2.0 (Bertioli et al., 2019). The RNAseq data were collected from various cultivars as available in the public databases. The data in the database are classified into four categories, which are accessible from a dropdown menu: Development, Nodule, Abiotic Stress, and Plant-Pathogen Interaction. As the focus of our group is on root nodule symbiosis, special attention has been given to this section. In the dropdown menu, one can find AhNGE-old, which contains RNAseq data generated in our lab for peanut nodule developmental series as published in Raul et al., 2022 (MPMI). Analysis of this data against three Arachis genomes: A. hypogaea (Tifrunner), A. duranensis, and A. ipaensis are available on the AhNGE-old page. This page will allow users to visualize genome-specific expression biases during peanut root nodule development. Users can retrieve gene expression for reference genes and novel transcript discovery tables by performing a search using A. duranensis, A. ipaensis, or A. hypogaea gene ID. Protein, DNA, and promoter sequences can be downloaded individually or in batches for all A. hypogaea. The OrthoFinder (Emms and Kelly 2015 and 2019) result among ten legumes and ten non-legume is also provided in the database for ease of comparative analyses. Legumes, (Arachis sp., Aeschynomene evenia, Chamaecrista fasciculata, Cicar arietinum, Glycine max, Lotus japonicus, Lupinus angustifolius, Medicago truncatula, Phaseolus vulgaris, Trifolium pratense); non-legumes, Parasponia andersonii, Alnus glutinosa, Casuarina glauca, Ceanothus thyrsiflorus, Datisca glomerata, Juglans regia, Prunus persica, Ziziphus jujuba, Populus trichocarpa and Arabidopsis thaliana. Additionally, protein sequences can be downloaded for five legumes and one non-legume species (Arachis, Glycine, Lotus, Cicer, Medicago, and Arabidopsis) used in the Orthofinder analysis. Users can search the database using any of the orthologous gene IDs. This database will be useful for comparative transcriptomic studies.