Figure 1.

An overview of non-coding RNAs in response to heat stress in plants. (A) miRNA-target network module involved in the heat stress response. The network is based on the changes in expression profiles of miRNAs and their targets in plants under heat stress. Black arrows represent regulatory effects (position or negative regulation); Green boxes: upregulated; red boxes: downregulated. (B) Schematic model of miR398 and TAS1, which play an important role in thermotolerance. (C) Schematic model of the heat-induced AS that led to a decrease in miR400 expression (modified from Yan et al., 2012). Under heat stress, an alternative splicing (AS) event occurs in the miR400-containing intron and generates a new host gene. In addition, a fragment containing the original branch site is excised, which induces the rest of the unrecognized intron including the miR400 hairpin to be retained in the host gene. The primary miR400 transcripts without splicing out are hardly processed into mature miR400 by Microprocessor. The number 4 represents the AS intron region. Abbreviations: SPL, squamosa promoter binding protein-like; ARF, auxin response factor; HOX, homeobox leucine zipper protein; PHV, phavoluta; REV, revoluta; TCP, teosinte branched/cycloidea protein; SCL, scarecrow-like; NAC, nascent polypeptide-associated complex; AFB, auxin receptor F-box proteins; PPR, pentatricopeptide repeat; AGO, argonaute; GAMYB, gibberellic acid MYB; TOE, target of eat; CSD, copper/zinc superoxide dismutase; CCS, copper chaperone for superoxide dismutase; TAS1, trans-acting siRNA precursor 1; HTT, heat-induced tas1 target; ROS, reactive oxygen species; HSF, heat stress transcription factor; HS, heat stress.