Influence of high natural field temperature during grain filling stage on the morphological structure and physicochemical properties of rice (Oryza sativa L.) starch

An investigation on the effect of Naphthalene acetic acid (NAA) on the changes of biochemical components of two varieties of rice (Oryza sativa L.), BRR1 dhan 29 and BRRI dhan 50 was carried out. Two concentrations of NAA, 100 and 200 ppm were used as foliar spray. In BRRI dhan 29, significant increases in chlorophyll a and chlorophyll b contents of leaf were observed due to both the treatments at the flowering stage, whereas, carotenoids at the grain filling stage only. But in BRRI dhan 50, the total leaf pigments decreased at the flowering and grain filling stage, but was significant in case of chlorophyll a at the flowering stage. Significant increases in protein content of leaf were recorded at the tillering and flowering stage of BRRI dhan 29 following 100 ppm NAA treatment. In BRRI dhan 50, the only significant increase was recorded at grain filling stage due to 200 ppm NAA treatment. In both the varieties carbohydrates, protein, fat, and energy content of grain increased due to both the treatments and the maximum increase in all the cases was recorded due to 100 ppm NAA treatment. Ash and moisture content of grain reduced following both the treatments in both the varieties, the maximum reduction was due to 100 ppm NAA treatment Asiat. Soc. Bangladesh, Sci. 40(2): 173-178, December 2014

Download Full-text

Physiological and Transcriptome Analyses of Early Leaf Senescence for ospls1 Mutant Rice (Oryza sativa L.) during the Grain-Filling Stage

International Journal of Molecular Sciences ◽

10.3390/ijms20051098 ◽

2019 ◽

Vol 20 (5) ◽

pp. 1098 ◽

Cited By ~ 8

Author(s):

Zhaowei Li ◽

Xinfeng Pan ◽

Xiaodong Guo ◽

Kai Fan ◽

Wenxiong Lin

Keyword(s):

Oryza Sativa ◽

Signaling Pathways ◽

Leaf Senescence ◽

Grain Filling ◽

Differentially Expressed ◽

Hormone Signaling ◽

Rna Seq ◽

Filling Stage ◽

Grain Filling Stage ◽

Early Leaf Senescence

Early leaf senescence is an important agronomic trait that affects crop yield and quality. To understand the molecular mechanism of early leaf senescence, Oryza sativa premature leaf senescence 1 (ospls1) mutant rice with a deletion of OsVHA-A and its wild type were employed in this study. The genotype-dependent differences in photosynthetic indexes, senescence-related physiological parameters, and yield characters were investigated during the grain-filling stage. Moreover, RNA sequencing (RNA-seq) was performed to determine the genotype differences in transcriptome during the grain-filling stage. Results showed that the ospls1 mutant underwent significant decreases in the maximal quantum yield of photosystem II (PSII) photochemistry (Fv/Fm), net photosynthesis rate (Pn), and soluble sugar and protein, followed by the decreases in OsVHA-A transcript and vacuolar H+-ATPase activity. Finally, yield traits were severely suppressed in the ospls1 mutant. RNA-seq results showed that 4827 differentially expressed genes (DEGs) were identified in ospls1 mutant between 0 day and 14 days, and the pathways of biosynthesis of secondary metabolites, carbon fixation in photosynthetic organisms, and photosynthesis were downregulated in the senescing leaves of ospls1 mutant during the grain-filling stage. In addition, 81 differentially expressed TFs were identified to be involved in leaf senescence. Eleven DEGs related to hormone signaling pathways were significantly enriched in auxin, cytokinins, brassinosteroids, and abscisic acid pathways, indicating that hormone signaling pathways participated in leaf senescence. Some antioxidative and carbohydrate metabolism-related genes were detected to be differentially expressed in the senescing leaves of ospls1 mutant, suggesting that these genes probably play response and regulatory roles in leaf senescence.

Download Full-text