The GI–CDF module of Arabidopsis affects freezing tolerance and growth as well as flowering

Abstract

SummaryPlants monitor and integrate temperature, photoperiod and light quality signals to respond to continuous changes in their environment. The GIGANTEA (GI) protein is central in diverse signaling pathways, including photoperiodic, sugar and light signaling pathways, stress responses and circadian clock regulation. Previously, GI was shown to activate expression of the key floral regulators CONSTANS (CO) and FLOWERING LOCUS T (FT) by facilitating degradation of a family of CYCLING DOF FACTOR (CDF) transcriptional repressors. However, whether CDFs are implicated in other processes affected by GI remains unclear. We investigated the contribution of the GI–CDF module to traits that depend on GI. Transcriptome profiling indicated that mutations in GI and the CDF genes have antagonistic effects on expression of a wider set of genes than CO and FT, whilst other genes are regulated by GI independently of the CDFs. Detailed expression studies followed by phenotypic assays showed that the CDFs function downstream of GI, influencing responses to freezing temperatures and growth, but are not necessary for proper clock function. Thus GI‐mediated regulation of CDFs contributes to several processes in addition to flowering, but is not implicated in all of the traits influenced by GI.

Identification of QTL Associated with Drought Tolerance in Andean Common Bean

“…The nearest common SNP to the peak region was ss715639424, located at 40.16 Mb. Another important gene in this region was Phvul.003G189300, 17.9 kb upstream of ss715639424 that encodes "CYCLING DOF FACTOR 3 (CDF3)," a member of the DOF family transcriptional factor that regulates flowering time by transcriptional repressing the activity of "CONSTANS (CO)" and "FLOWERING LOCUS (FT)" (Fornara et al, 2009(Fornara et al, , 2015. A search of possible candidate genes within a 35-kb interval from marker ss715639424 resulted in nine genes within a 65.9-kb region, and two genes were considered positional candidates.…”

Shining a light on the Arabidopsis circadian clock

“…Diurnal changes in cellular processes controlled by the clock allow plants to anticipate, and therefore better survive, a range of stresses (Sanchez, Shin, & Davis, ). Diurnal changes have been shown to occur in cold/freezing tolerance (Fornara et al, ; Nakamichi et al, ), drought tolerance (Habte, Muller, Shtaya, Davis, & von Korff, ), pathogen response (Shin, Heidrich, Sanchez‐Villarreal, Parker, & Davis, ; Wang et al, ), and photosynthesis (Pyl et al, ). This synchronization is the product of a large number of rhythmically regulated cellular processes (Bujdoso & Davis, ; Hanano et al, ), many of which are triggered by light perception (Wenden et al, ).…”

WITHDRAWN: Physiological and biochemical characterization of tomato transgenic lines overexpressing Arabidopsis thaliana cold responsive-element binding factor 3 (AtCBF3) gene under chilling stress

“…The transcription protein AtCBF3 serves as a main regulator of various genes under cold stress to improve tolerance against cold stress (Fornara et al, 2015). To investigate the role of AtCBF3 in the possible regulation of multiple genes, T2 transgenic lines were exposed to various chilling shocks and transpiration rate were measured in transgenic as well as WT plants.…”

“…Consequently, there is exigency to develop cold tolerant tomato. Cold responsive-element binding factor 3 (CBF3) binds to a DNA regulatory element termed as CRT/DRE containing the same motif (CCGAC), regulating the expression of cold stress-responsive genes and enhances chilling tolerance in tomato by accumulating cryoprotecting proteins and osmolytes such as sucrose and proline (Kidokoro et al, 2015;Park et al, 2015;Fornara et al, 2015). Plants defense system is strengthened against chilling stress accumulating compatible solutes like total soluble sugars which protect plant cells through many ways; acting as osmoprotectants, a source of nutrients, controlling plant metabolism and protecting cellular membranes (Shao et al, 2006).…”