Further Characterization of a Rice AGL12 Group MADS-Box Gene,OsMADS26       

Abstract

Plant MADS-box genes can be divided into 11 groups. Genetic analysis has revealed that most of them function in floweringtime control, reproductive organ development, and vegetative growth. Here, we elucidated the role of OsMADS26, a member of the AGL12 group. Transcript levels of OsMADS26 were increased in an age-dependent manner in the shoots and roots. Transgenic plants of both rice (Oryza sativa) and Arabidopsis (Arabidopsis thaliana) overexpressing this gene manifested phenotypes related to stress responses, such as chlorosis, cell death, pigment accumulation, and defective root/shoot growth. In addition, apical hook development was significantly suppressed in Arabidopsis. Plants transformed with the OsMADS26-GR (glucocorticoid receptor) fusion construct displayed those stress-related phenotypes when treated with dexamethasone. Microarray analyses using this inducible system showed that biosynthesis genes for jasmonate, ethylene, and reactive oxygen species, as well as putative downstream targets involved in the stress-related process, were up-regulated in OsMADS26-overexpressing plants. These results suggest that OsMADS26 induces multiple responses that are related to various stresses.

OsMADS26 negatively regulates resistance to pathogens and drought tolerance in rice.

“…Some of them are involved in development by controlling stress-related processes, such as OsMADS3, which is involved in reactive oxygen species homeostasis during anther development, and OsMADS29, which controls cell degeneration during seed development (Hu et al, 2011;Yang et al, 2012). A possible specific involvement of rice MADS genes in stress response has been reported only for OsMADS26, the rice ortholog of AGL12 (Lee et al, 2008b. In Arabidopsis, AGL12 regulates cell proliferation in the root apical meristem as well as flowering transition and was suggested to control root secondary cell wall synthesis (Tapia-López et al, 2008;Chávez Montes et al, 2014).…”

“…In rice, OsMADS26 OX causes a severe stress phenotype that generally leads to plant death. Expression of OsMADS26 under the control of a dexamethasone-inducible promoter provokes the differential regulation of genes involved in jasmonic acid biosynthesis and reactive oxygen species production (Lee et al, 2008b).…”

Identification of an Arabidopsis Nodulin-Related Protein in Heat Stress

“…The AtNRP1-overexpressing transgenic plants showed decreased thermotolerance at different growth stages and the null mutation at the AtNRP1 gene was the same as WT under heat stress, which indicated that the single-gene mutation of AtNRP1 was insufficient to alter heat tolerance. There are many cases where a T-DNA KO line does not show any phenotype because of functional complementation of related genes (Cutler and McCourt, 2005;Higashi et al, 2008;Lee, et al, 2008). AtNRP1 may have functional overlap with other heat-related genes, and these functional-overlap genes may compensate for the lack of function of AtNRP1, so there are no obvious phenotype differences between nrp1 and WT under nomal conditions or heat stress.…”

Woody Stem Galls Interact With Foliage to Affect Community Associations

“…DIECA rapidly and efficiently causes the chemical reduction of hydroperoxyoctadecatrienoic acid, the product of the oxidation of linolenic acid by lipoxygenase, which prevents its cyclization and subsequent conversion to downstream products, including JA (Farmer et al 1994). DIECA has been successfully used as a JAinhibitor on a wide range of plant species (Piel et al 1997;Gantet et al 1998;Lee et al 1998;Menke et al 1999;Watanabe et al 2000; Garcia-Ponce and Rocha-Sosa 2000; Bulgakov et al 2004;Saltveit et al 2005;Hu and Zhong 2008;Lee et al 2008;Peebles et al 2009). Elucidation of how JA manipulation influences gall characteristics could improve the interpretation of studies that investigate gall ecology.…”