Identification of aluminum-responsive microRNAs in Medicago truncatula by genome-wide high-throughput sequencing

Abstract

MicroRNAs (miRNAs) play important roles in response of plants to biotic and abiotic stresses. Aluminum (Al) toxicity is a major factor limiting plant growth in acidic soils. However, there has been limited report on the involvement of miRNAs in response of plants to toxic Al(3+). To identify Al(3+)-responsive miRNAs at whole-genome level, high-throughput sequencing technology was used to sequence libraries constructed from root apices of the model legume plant Medicago truncatula treated with and without Al(3+). High-throughput sequencing of the control and two Al(3+)-treated libraries led to generation of 17.1, 14.1 and 17.4 M primary reads, respectively. We identified 326 known miRNAs and 21 new miRNAs. Among the miRNAs, expression of 23 miRNAs was responsive to Al(3+), and the majority of Al(3+)-responsive mRNAs was down-regulated. We further classified the Al(3+)-responsive miRNAs into three groups based on their expression patterns: rapid-responsive, late-responsive and sustained-responsive miRNAs. The majority of Al(3+)-responsive miRNAs belonged to the 'rapid-responsive' category, i.e. they were responsive to short-term, but not long-term Al(3+) treatment. The Al(3+)-responsive miRNAs were also verified by quantitative real-time PCR. The potential targets of the 21 new miRNAs were predicted to be involved in diverse cellular processes in plants, and their potential roles in Al(3+)-induced inhibition of root growth were discussed. These findings provide valuable information for functional characterization of miRNAs in Al(3+) toxicity and tolerance.

Repression of Growth Regulating Factors by the MicroRNA396 Inhibits Cell Proliferation by UV-B Radiation in Arabidopsis Leaves

“…In particular, miR396 has been previously reported to be regulated by various stresses in different plants species, such as drought (Zhou et al, 2010;Kantar et al, 2011;Li et al, 2011;T. Wang et al, 2011), cold (Zhou et al, 2008), aluminium (Al 3+ ; Chen et al, 2012), cadmium (Cd 2+ ; Ding et al, 2011), salt, and alkali stress (Ding et al, 2009;Gao et al, 2010). For example, transgenic rice (Oryza sativa) and Arabidopsis plants constitutively overexpressing rice miR396c show reduced salt and alkali stress tolerance compared with that of wild-type plants (Gao et al, 2010).…”

Identification of Drought-Responsive microRNAs from Roots and Leaves of Alfalfa by High-Throughput Sequencing

“…Novel miRNAs were predicted by using Mireap [39]. Novel miRNA candidates were identified according to the criteria reported by [40]. The normalization of reads count and calculation of log Fold change were processed as [18] described.…”

Role of microRNA319 in creeping bentgrass salinity and drought stress response

“…[1][2][3][4][5][6] In recent years, an increasing number of studies on how miR319 is involved in plant stress response were conducted to define the function of miR319. For example, a hypothetical model of how miR319 regulates plant cold stress response in sugarcane was proposed.…”