LEAFY HEAD2, which encodes a putative RNA-binding protein, regulates shoot development of rice

Abstract

During vegetative development, higher plants continuously form new leaves in regular spatial and temporal patterns. Mutants with abnormal leaf developmental patterns not only provide a great insight into understanding the regulatory mechanism of plant architecture, but also enrich the ways to its modification by which crop yield could be improved. Here, we reported the characterization of the rice leafy-head2 (lhd2) mutant that exhibits shortened plastochron, dwarfism, reduced tiller number, and failure of phase transition from vegetative to reproductive growth. Anatomical and histological study revealed that the rapid emergence of leaves in lhd2 was resulted from the rapid initiation of leaf primordia whereas the reduced tiller number was a consequence of the suppression of the tiller bud outgrowth. The molecular and genetic analysis showed that LHD2 encodes a putative RNA binding protein with 67% similarity to maize TE1. Comparison of genome-scale expression profiles between wild-type and lhd2 plants suggested that LHD2 may regulate rice shoot development through KNOX and hormone-related genes. The similar phenotypes caused by LHD2 mutation and the conserved expression pattern of LHD2 indicated a conserved mechanism in controlling the temporal leaf initiation in grass.

The function of the RNA-binding protein TEL1 in moss reveals ancient regulatory mechanisms of shoot development

“…Thus, TEL proteins represent a specific class of RRM-containing RBPs because of its divergent RRM3. Besides, TEL genes were shown to regulate leaf initiation and development in monocots (Veit et al 1998;Kawakatsu et al 2006;Xiong et al 2006), whereas the other Mei2-like genes were linked to meiosis (Hirayama et al 1997;Kaur et al 2006). The fact that TEL and other Mei2p-like proteins seem to participate in distinct developmental processes, suggests the potential importance of the TEL-specific insertion within the RRM3 of TEL proteins.…”

Structure and vascular tissue expression of duplicated TERMINAL EAR1-like paralogues in poplar

“…In fact, te1 maize mutants, named because of the ear-like inXorescence that forms in place of the normal terminal tassel (Matthews et al 1974), also exhibit abnormal leaf initiation and development, abnormally short internodes and tassel feminisation (Veit et al 1998). Similarly, pla2/lhd2 rice mutants exhibit shortened plastochron, precocious leaf maturation and the conversion of inXorescence branches to vegetative structures (Kawakatsu et al 2006;Xiong et al 2006). Expression analyses of TEL genes in Poaceae revealed TEL transcripts in many diVerentiating cell types of the plant, suggesting that TEL could regulate tissue diVerentiation in Poaceae, including vascular tissues (Paquet et al 2005).…”

“…The founding member of the TEL group, the TERMI-NAL EAR1 (TE1) gene of maize, was proposed to regulate leaf initiation and development (Veit et al 1998), a function also attributed to the rice homologue, PLASTO-CHRON2/LEAFY HEAD2 (Kawakatsu et al 2006;Xiong et al 2006). In fact, te1 maize mutants, named because of the ear-like inXorescence that forms in place of the normal terminal tassel (Matthews et al 1974), also exhibit abnormal leaf initiation and development, abnormally short internodes and tassel feminisation (Veit et al 1998).…”

Genetic analysis and gene cloning of a triangular hull 1 (tri1) mutant in rice (Oryza sativa L.)

“…To date, several genes controlling rice panicle development have been reported, and most of these were identified as mutants; examples are leafty head (lhd) [14,15], branched floretless 1 (bfl1) [16], short panicle 1 (sp1) [17], aberrant spikelet and panicle 1 (asp1) [18], floral organ number (fon) [6,18,19], and enclosed panicle 2 (esp2) [20]. Also, other genes have been reported to be associated with rice hull development, including frizzy panicle (fzp) [21], abnormal hull (ah) [22], long sterile lemma (gl) [23], elongated empty glume (ele) [24], leafy hull sterile 1 (lhs1) [25], depressed palea (dp) [26], and triangular hull (th1) [11].…”