Genome-Wide Identification and Expression Analysis of the Aquaporin Gene Family in Lycium barbarum during Fruit Ripening and Seedling Response to Heat Stress

Abstract

Plant–water relations mediated by aquaporins (AQPs) play vital roles in both key plant growth processes and responses to environmental challenges. As a well-known medicinal and edible plant, the harsh natural growth habitat endows Lycium plants with ideal materials for stress biology research. However, the details of their molecular switch for water transport remain unclear. In the present work, we first identified and characterized AQP family genes from Lycium (L.) barbarum at the genome scale and conducted systemic bioinformatics and expression analyses. The results showed that there were 38 Lycium barbarum AQPs (LbAQPs) in L. barbarum, which were classified into four subfamilies, including 17 LbPIP, 9 LbTIP, 10 LbNIP, and 2 LbXIP. Their encoded genes were unevenly distributed on all 12 chromosomes, except chromosome 10. Three of these genes encoded truncated proteins and three genes underwent clear gene duplication events. Cis-acting element analysis indicated that the expression of LbAQPs may be mainly regulated by biotic/abiotic stress, phytohormones and light. The qRT-PCR assay indicated that this family of genes presented a clear tissue-specific expression pattern, in which most of the genes had maximal transcript levels in roots, stems, and leaves, while there were relatively lower levels in flowers and fruits. Most of the LbAQP genes were downregulated during L. barbarum fruit ripening and presented a negative correlation with the fruit relative water content (RWC). Most of their transcripts presented a quick and sharp upregulation response to heat stress following exposure of the 2-month-old seedlings to a 42 °C temperature for 0, 1, 3, 12, or 24 h. Our results proposed that LbAQPs were involved in L. barbarum key development events and abiotic stress responses, which may lay a foundation for further studying the molecular mechanism of the water relationship of Lycium plants, especially in harsh environments.

Genome-Wide Identification and Gene Expression Analysis of Sweet Cherry Aquaporins (Prunus avium L.) under Abiotic Stresses

“…Due to their function of transporting resources, aquaporins are ubiquitous protein channels that participate in various developmental and stress response processes [ 11 , 12 , 13 , 14 , 15 , 44 , 45 ]. Thus, the regulation of gene expression of the numerous isoforms of aquaporins in response to stresses such as root hypoxia [ 10 ], drought [ 46 , 47 ], salinity [ 48 , 49 ], cold [ 50 , 51 , 52 , 53 ], heat [ 54 , 55 ] and combinations of them [ 56 ] have been consistently reported.…”

“…This pattern is like what was found in Cucumis sativus , where members of the same subfamily (i.e., CsPIP1 ; 1 , CsPIP2 ; 1 , CsTIP4 ; 1 , and CsNIP3 ; 1 ) lacked the ARE motif [ 67 ]. However, a different pattern was observed in Lycium barbarum , where 16 out of 38 of their aquaporins did not contain the ARE motif [ 55 ]. Some aquaporin genes were exceptions to other stress-responsive cis-acting elements.…”

“…The presence of aquaporins has been widely documented in all plant organs or tissues, but the numerous isoforms present gene expressions subjected to temporal and spatial regulation [ 45 , 55 , 108 , 109 , 110 ]. Such transcriptional behavior may be associated with specific roles in the physiological processes of each organ.…”

Editorial for the Special Issue “Genetic Sight: Plant Traits during Postharvest”

“…As the scope of research has expanded, studies have increasingly focused on the molecular mechanisms regulating a specific trait. This special issue incorporated about the regulation of flower development by CYC-like genes with their different functions and phylogenetic relationships in plant groups [ 5 ], function of DUF26 domain-containing genes to regulate the submergence tolerance of wild rice [ 6 ], and LbPYLs was suggested as good candidates to enhance Lycium resistance to drought and hot environments [ 7 ].…”

“…Generally, as this special issue belongs to the section “Molecular Plant Sciences” and considering the interest of authors to contribute in this special issue, the editorial team tried to observe the broad spectrum, and eleven research articles [ 2 , 3 , 4 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ] and two reviews [ 1 , 5 ] were included.…”