Supplementary Materialsijms-19-02339-s001. Genetic analysis revealed that this premature senescence leaf phenotype was controlled by a single recessive nuclear gene which was finally mapped in a 47 kb region on the short arm of chromosome 7, covering eight candidate open reading frames (ORFs). No comparable genes controlling a premature senescence leaf phenotype have been identified in the region, and cloning and functional analysis of the gene is currently underway. [6], and [16], it was reported that numerous DNA fragmentation events and cell death occurred in the leaves with the initiation and progression of premature senescence phenotype. In the onset and progression of senescence process, plants also integrate multiple internal and external signals to respond to various types of endogenous and exogenous aging-effected factors through intricate regulatory pathways [17,18]. Abscisic acid (ABA) plays an important role in environmental stress responses and, thus, leaf longevity [5]. Consistently, ABA VX-950 inhibitor is also thought to facilitate leaf aging and abscission, and both altered expression levels of ABA metabolism-related genes and increased levels of endogenous ABA have been detected in the leaves that undergo senescence [18,19]. Furthermore, a large number of differentially expressed genes (DEGs) have been recognized in leaf senescence plants, induced by biotic or/and abiotic stresses, and exogenous ABA treatment has been reported to cause the upregulation of several senescence-associated genes (SAGs) and chlorophyll degradation-related genes (CDGs) known to accelerate leaf senescence, such as (([24], [20] and [25]. Premature leaf senescence has a great impact on the crop VX-950 inhibitor yield and grain quality, while the underlying molecular mechanism of senescence is still poorly comprehended [26]. Here, a novel rice premature senescence leaf mutant, tentatively named showed more rapid chlorophyll degradation both under field conditions and after ABA treatment. Furthermore, the altered expression of genes related to SAGs, CDGs, and ABA metabolism, in and ABA signaling pathway. Our results would facilitate the study around the molecular mechanism of premature leaf senescence in rice, and also provide a foundation for isolation and functional analysis of VX-950 inhibitor mutant exhibited a premature senescence leaf phenotype (yellowish leaves) and dwarfism under the field and greenhouse conditions in Hangzhou, Zhejiang, China, and Lingshui, Hainan, China. The leaf senescence phenotype appeared in about 25 days after germination (DAG25) and lasted until the mature stage under field conditions, compared with the wild type (WT) Zhongjian 100, (Physique 1A,C). In mutant showed a decreased herb height with shortened internodes at the seedling, tillering, and mature stages compared to WT (Physique 1A,B,E). Other major agronomic characteristics, including the panicle length, number of packed grains per herb, and seed-setting rate, were all amazingly reduced in (Table S1), indicating that the premature leaf senescence in would impose a negative effect on the herb yield. To investigate the direct reason for dwarfism in (Physique 1F,G). The results showed that this cell length was significantly reduced in the mutant, while the cell width was comparable between and WT (Physique 1H,I), which indicated that this dwarf phenotype of was directly resulted from your reduced cell length of the stems. Open in a separate window Physique 1 Phenotypes of wild type (WT) and at the tillering stage. (B) WT and seedlings at DAG15. (C) WT and at DAG30. L1, L2, and L3 indicate the top three leaves of WT and in (C). Mouse monoclonal to FOXP3 (E) Internode length of the main stem at the mature stage in WT and (F,G) Longitudinal section of the third internode of WT (F) and (G) at the mature stage. Level bar = 100 m. (H,I) Longitudinal cell length (H) and cell width (I) of WT and Level bar = 20 cm in (A) and level bar = 2 cm in (B,C). Values are means SD (= 3); ** indicates significance at 0.01 and * indicates significance at 0.05 by Students test. 2.2. Alterations of Chlorophyll Contents, Chloroplast Ultrastructure, and Photosynthetic Parameters To examine whether the yellowing phenotype was associated with the chlorophyll level, we measured the chlorophyll contents of mutant at DAG15 before senescence, DAG30, and DAG60 after senescence. VX-950 inhibitor The results showed that this chlorophyll levels were comparable between WT and at DAG15, while there was a significant reduction of chlorophyll levels in at DAG30, and the upper five leaves at DAG60 compared with WT (Physique 2A,B). Furthermore, a significantly decreased chlorophyll content of the functional flag leaves was also observed in at the heading stage (Physique 2C). Open in a separate window Physique 2 Chlorophyll contents, chloroplast structures, and photosynthetic.