Peg Biology: Deciphering the Molecular Regulations Involved During Peanut Peg Development

Abstract

Peanut or groundnut is one of the most important legume crops with high protein and oil content. The high nutritional qualities of peanut and its multiple usage have made it an indispensable component of our daily life, in both confectionary and therapeutic food industries. Given the socio-economic significance of peanut, understanding its developmental biology is important in providing a molecular framework to support breeding activities. In peanut, the formation and directional growth of a specialized reproductive organ called a peg, or gynophore, is especially relevant in genetic improvement. Several studies have indicated that peanut yield can be improved by improving reproductive traits including peg development. Therefore, we aim to identify unifying principles for the genetic control, underpinning molecular and physiological basis of peg development for devising appropriate strategy for peg improvement. This review discusses the current understanding of the molecular aspects of peanut peg development citing several studies explaining the key mechanisms. Deciphering and integrating recent transcriptomic, proteomic, and miRNA-regulomic studies provide a new perspective for understanding the regulatory events of peg development that participate in pod formation and thus control yield.

Genomic Analysis of Sugar Transporter Gene Family in Cultivated Peanut (Arachis Hypogaea): Evolution, Expression Profiles and Gene Variation

“…The functional roles of some AhSTP genes involved in speci c peanut physiological process were inferred through valuable clues. For example, AhSTP3 and AhSTP19, a segmental gene pair, exhibited high expression in the stage peg tip developed to form a pod, which is a stage embryo cell division facilitating geocarpic pod [30]. While their orthologs in Arabidopsis, AtSTP12, located in the inner integument, could uptake sugar to supply the embryo development [41], indicating that AhSTP3/19 may share the similar function in cultivated peanut.…”

“…Peg is an important yield related trait, with the capacity for embryo positive gravitropism transportation and penetrating the soil to form subterranean pods [30]. The development stage from peg to pod is a biological process participated by phytohormone, signals, energy, et al [30], while monosaccharides (e.g., glucose, fructose, and mannose) are important to generate energy and synthesize cellulose and starch [4,21]. Therefore, it is important to investigate the expression of AhSTP genes in the peg and pod of cultivated peanut and dissect the potential roles of these genes in sugar distribution.…”

“…Genetic, cytogenetic, phylogeographic and molecular evidences have suggested that cultivated peanut is an allotetraploid (AABB, 2n = 4x = 40) formed through hybridization between A. duranensis (AA, 2n = 2x = 20) and A. ipaensis (BB, 2n = 2x = 20) [24][25][26][27][28][29]. It's speci c in ower stalks (peg) elongation and developing pods under the ground, which contains sugar transportation, accumulation and transition processes [30]. But until now, little information on STP gene family expression in peg elongation, pod development and other tissues of peanut is available for us.…”

“…relationship of STP proteins in ve plant species. Phylogenetic analysis of 111 STP proteins from A.hypogaea (36), A.duranensis(15),A.ipaënsis (16), A.thaliana(14)and G.max(30) are marked with red squares, yellow triangles, green triangles, Purple diamonds and blue circles, respectively. Four groups were marked with different background colors.…”

Alternative splicing profiling provides insights into the molecular mechanisms of peanut peg development

“…Peanut (Arachis hypogaea L.) is a widely cultivated oil and cash crop in the world. As one of the members of the Fabaceae family, however, peanut is a unique plant distinct from other legumes, which has the features of the aerial cleistogamous flowers and the subterranean pods [1]. After overground double fertilization, the gynophore develops a specialized geotropic aerial peg by elongation of meristematic cells locating in basal of ovary.…”