OsHAP3 genes regulate chloroplast biogenesis in rice

Abstract

SummaryWe have isolated three genes that potentially encode a HAP3/nuclear factor-YB (NF-YB)/CCAAT binding factor-A (CBF-A) subunit of a CCAAT-box binding complex in rice (Oryza sativa), and named them OsHAP3A, OsHAP3B and OsHAP3C. These genes were expressed in various organs including leaves. In the transgenic rice plants with antisense or RNAi construct of OsHAP3A, reduced expression of not only OsHAP3A but also OsHAP3B and OsHAP3C was observed. These plants had pale green leaves, in which the amount of chlorophyll was reduced and chloroplasts were degenerated. Lamella was not well developed and accumulation of starch was not detected. The degenerated chloroplast formation was accompanied by reduced expression of nuclear-encoded photosynthesis genes such as RBCS and CAB, while expression of chloroplast-encoded genes was not affected or rather increased. These results suggest that one or more OsHAP3 genes regulate the expression of nuclear-encoded chloroplast-targeted genes and normal development of chloroplasts.

OsNF-YC2 and OsNF-YC4 proteins inhibit flowering under long-day conditions in rice

“…S1, S2), the expression of some OsNF-Y genes was detected in all tissues tested in this study (Fig. 6), and the report of Thirumurugan et al (2008) that OsNF-YB2, which is involved in chloroplast biogenesis (Miyoshi et al 2003), interacts with OsNF-YC subunits in yeast. OsNF-YC4-RNAi and OsNF-YC6-RNAi plants could be due to the functional redundancy of these genes with the homologous OsNF-YC genes (Thirumurugan et al 2008;Petroni et al 2012;Laloum et al 2013).…”

DTH8 Suppresses Flowering in Rice, Influencing Plant Height and Yield Potential Simultaneously

“…The HAP complex consists of three subunits: HAP2/NF-YA/CBF-B, HAP3/NF-YB/CBF-A, and HAP5/NF-YC/CBF-C. Each subunit of the HAP complex contains a conserved domain that is responsible for DNA binding or protein-protein interaction. Although many genes encoding HAP subunits have been found so far (Edwards et al, 1998;Gusmaroli et al, 2001Gusmaroli et al, , 2002Thirumurugan et al, 2008), only a few of them have been studied (Lotan et al, 1998;Meinke, 1992;West et al, 1994;Kwong et al, 2003;Miyoshi et al, 2003). In this study, a rice HAP3 gene, DTH8, has been proven to play an important role in the regulation of flowering time, plant height, and yield potential.…”

“…Also, two NF-YB/ HAP3 genes, LEAFY COTY-LEDON1 and LEC1-LIKE, were shown to be important regulators of embryogenesis (Lotan et al, 1998;Kwong et al, 2003). In rice, OsHAP3A or its homologs, OsHAP3B and OsHAP3C, were shown to control chloroplast biogenesis (Miyoshi et al, 2003). However, the functions of other members of the NF-YB/HAP3 gene families and all members of the NF-YA/HAP2 and NF-YC/HAP5 in Arabidopsis and rice are still unknown.…”

The Evolutionary History of CBF Transcription Factors: Gene Duplication of CCAAT – Binding Factors NF-Y in Plants

“…These observations indicate that plant NF-Y subunits might act as general transcription factors, as in mammals (Yamamoto et al, 2009). Although a complete functional plant NF-Y complex has not yet been described, the individual subunits are known to be involved in a number of important physiological processes, such as specific developmental processes and response to environmental stimuli (Lotan et al, 1998;Kusnetsov et al, 1999;Miyoshi et al, 2003;Ben-Naim et al, 2006;Combier et al, 2006;Wenkel et al, 2006;Cai et al, 2007;Nelson et al, 2007;Warpeha et al, 2007;Siefers et al, 2009). A well-established example is the NF-YB subunit gene called LEAFY COTYLEDON-1 (LEC1), which specifically controls embryo development, especially the maturation phase.…”

“…This Arabidopsis NF-Y expansion is a general feature of the plant lineage, including monocots and eudicots. In rice (Oryza sativa), for example, 11 genes were identified coding for the NF-YA subunit, 10 for NF-YB and 8 for NFY-C. Four of the rice NF-YB subunits have been characterized and at least one of these genes is involved in chloroplast development (Miyoshi et al, 2003;Yazawa and Kamada, 2007). Interestingly, the moss Physcomitrella patens and the lycophyte Selaginella mollendorffii possess single genes coding for NF-YA subunits whereas the other subunits are encoded by multiple genes (Table 1).…”