microRNAs Associated with Drought Response in the Bioenergy Crop Sugarcane (Saccharum spp.)

Abstract

Sugarcane (Saccharum spp.) is one of the most important crops in the world. Drought stress is a major abiotic stress factor that significantly reduces sugarcane yields. However the gene network that mediates plant responses to water stress remains largely unknown in several crop species. Although several microRNAs that mediate post-transcriptional regulation during water stress have been described in other species, the role of the sugarcane microRNAs during drought stress has not been studied. The objective of this work was to identify sugarcane miRNAs that are differentially expressed under drought stress and to correlate this expression with the behavior of two sugarcane cultivars with different drought tolerances. The sugarcane cultivars RB867515 (higher drought tolerance) and RB855536 (lower drought tolerance) were cultivated in a greenhouse for three months and then subjected to drought for 2, 4, 6 or 8 days. By deep sequencing of small RNAs, we were able to identify 18 miRNA families. Among all of the miRNAs thus identified, seven were differentially expressed during drought. Six of these miRNAs were differentially expressed at two days of stress, and five miRNAs were differentially expressed at four days. The expression levels of five miRNAs (ssp-miR164, ssp-miR394, ssp-miR397, ssp-miR399-seq 1 and miR528) were validated by RT-qPCR (quantitative reverse transcriptase PCR). Six precursors and the targets of the differentially expressed miRNA were predicted using an in silico approach and validated by RT-qPCR; many of these targets may play important roles in drought tolerance. These findings constitute a significant increase in the number of identified miRNAs in sugarcane and contribute to the elucidation of the complex regulatory network that is activated by drought stress.

Constitutive Expression of Rice MicroRNA528 Alters Plant Development and Enhances Tolerance to Salinity Stress and Nitrogen Starvation in Creeping Bentgrass

“…1). This suggests that miR528 is regulated by abiotic stress, consistent with observations in rice, maize, and sugarcane (Ding et al, 2009;Xu et al, 2011;Ferreira et al, 2012;Nischal et al, 2012). …”

“…Responds to Salt, Drought, and N Deficiency Stresses miR528 has previously been implicated in plant responses to drought, salt, and N deficiency in annual species (Ding et al, 2009;Xu et al, 2011;Ferreira et al, 2012;Nischal et al, 2012). To study its role in perennial grass species, we first examined its expression in response to various abiotic stresses in creeping bentgrass.…”

“…Recently, an evolutionarily conserved monocotspecific miRNA, miR528, was identified to respond to multiple stresses, including salt, drought, low-temperature, submergence, nitrate starvation, and arsenite and arsenate stresses in maize (Zea mays), sugarcane (Saccharum officinarum), phalaenopsis orchid (Phalaenopsis aphrodite), and rice (Oryza sativa; Zhang et al, 2008;Xu et al, 2011;Ferreira et al, 2012;Nischal et al, 2012;Sharma et al, 2015). In addition, deep sequencing analysis shows that miR528 responds to diazotrophic bacteria in maize and might be involved in cytoplasmic male sterility in rice anther (Thiebaut et al, 2014;Yan et al, 2015).…”

Physiological limitations in two sugarcane varieties under water suppression and after recovering

“…With the outcome on sugarcane genome mapping, novel possibilities can appear such as genetic improvement assisted by molecular markers (Edwards and Batley 2010, Buckeridge et al 2012, Ferreira et al 2012, Gentile et al 2013. Thus, physiological studies on sugarcane may identify varieties more tolerant to water stress and, ultimately, improve plant breeding.…”

Isolamento, caracterização e identificação de leveduras killer de caldo de cana de açúcar

“…The increasing energy demand and depletion of oil reserves motivate the search for alternative energy resources. Sugarcane is one of the most important crops in the world, and Brazil is the largest producer of this plant and the second biggest producer of ethanol using sugarcane as raw material (FERREIRA et al, 2012). However, ethanol production is affected by undesirable yeasts from sugarcane and the environment.…”