microRNAs contribute to enhanced salt adaptation of the autopolyploid Hordeum bulbosum compared with its diploid ancestor

Abstract

MicroRNAs contribute to enhanced salt adaptation of the autopolyploid Hordeum bulbosum compared to its diploid ancestor By Beibei LiuSeveral studies have shown that autopolyploid species can tolerate abiotic stresses better than their diploid ancestor. However, the underlying molecular mechanism is poorly understood. Whole genome duplication can result in the expansion of miRNA families, and the innovative miRNA-target interaction is vital for adaptive response to various environments. The new microRNAs which were induced by genome duplication, also associated with stress response, and the distinctive microRNA networks in tetraploid and diploid Hordeum bulbosum by using high-throughput sequencing. Five miRNAs affected by genome doubling were involved in salt stress response. Of these, miR528b-3p was only detected in the tetraploid plants, and down -regulated in salt stress tetraploid plants relative to that in tetraploid check (CK). Moreover, it was found that miR528b-3p was not only involved in DNA replication and repair but also affected salt stress response. Finally, distinguished microRNAs-targets regulatory networks in both diploid and tetraploid plants were discovered. July 2017 III DedicationI would like to dedicate this work to my boyfriend Chao Wang who has graduated last year. To wait for me graduating, he stays here for another year with me. There is no doubt that without his support and help in my work, I could not finish this work. I also want to express my special thanks to my loving parents. Although they didn't live with me here, it is their words of encouragement and love that support me to complete my graduate study.IV

Enhanced ROS scavenging and sugar accumulation contribute to drought tolerance of naturally occurring autotetraploids in Poncirus trifoliata

“…Such alterations may include larger organ structure (Dudits et al ., ), slower growth (Allario et al ., ), improved fruit yield (Hussain et al ., ) and different anatomical features (Allario et al ., ). In addition, accumulating evidence demonstrate that autotetraploids exhibit dramatically enhanced tolerance to a variety of abiotic stresses, including cold (Oustric et al ., ), drought (Allario et al ., ), salt (Liu and Sun, ; Ruiz et al ., ; Tu et al ., ), heat (Zhang et al ., ), chromium toxicity (Balal et al ., ) and boron excess (Ruiz et al ., ). These observations provide the impetus for additional research to understand the underlying basis for many of these desirable performance and traits resulting from autopolyploidy.…”

“…While the broad advantages of historical or evolutionary autopolyploidy on environmental adaption are commonly recognized (Comai, ; Fasano et al ., ; Parisod et al ., ), the improved stress tolerance of neopolyploids and the underlying molecular mechanisms have not been explicitly investigated. With the advent of high throughput sequencing, differences in transcriptome and miRNAome profiles between diploids and polyploids in the presence of a given stressor are investigated (Allario et al ., ; Cao et al ., ; Fan et al ., ; Liu and Sun, ; Stupar et al ., ). These studies demonstrated that a limited number of the transcribed genes are differentially expressed, implying that polyploidization may cause subtle changes in the expression of specific genes responsible for stress tolerance (Allario et al ., ; Tan et al ., ).…”

Review and in silico analysis of fermentation, bioenergy, fiber, and biopolymer genes of biotechnological interest in Agave L. for genetic improvement and biocatalysis

“…Polyploid plant species display morphological and physiological characteristics that make them more attractive for industrial applications than their lower ploidy counterparts . Presence of polyploid species in extreme environments, such as subarctic regions, glaciers, and arid zones, also makes them suitable for biotechnological purposes because their cultivation could diminish economic losses due to their higher tolerance to biotic and abiotic stress factors …”

“…7 Presence of polyploid species in extreme environments, such as subarctic regions, glaciers, and arid zones, 78,79 also makes them suitable for biotechnological purposes because their cultivation could diminish economic losses due to their higher tolerance to biotic and abiotic stress factors. 8,79,80 Polyploidy is a little explored fundamental biological phenomenon in Agave. The genus is of possible allopolyploid origin having a basic chromosome number of n = 30, a bimodal karyotype with 5 long acrocentric and 25 small metacentric or submetacentric chromosomes, and ploidy level of its species varies from diploid (2n = 2x = 60) to octoploid (2n = 8x = 240).…”

Phenotypic and seed structural comparison in hybrids of different Brassica rapa and B. oleracea

“…In nature, there are many native autopolyploids like Solanum tuberosum L., and allopolyploids like Dendranthema morifolium (Ramat) Tzvel. and Brassica napus L. Compared to diploid species, polyploids have been reported to show advantages in stress resistance, adaptation, biomass and grain yield, seed quality (e.g., oil content) and other important agronomic traits (Girke, Schierholt, & Becker, ; Liu & Sun, ; Meng et al, ; Saleh, Allario, Dambier, Ollitrault, & Morillon, ). In the past decades, the changes after polyploidization were revealed in support with the genome data and other next generation sequencing data, including gene rearrangement, genomic structure variation, loss and gain of functions, transposon activation, epigenetic changes and variations of gene expression level and pattern (Chen, ; Gaeta, Pires, Iniguez‐Luy, Leon, & Osborn, ; Jackson & Chen, ; Kashkush, Feldman, & Levy, ; Liu et al, ).…”