Rice Male Development under Drought Stress: Phenotypic Changes and Stage-Dependent Transcriptomic Reprogramming

Abstract

Drought affects rice reproduction and results in severe yield loss. The developmental defects and changes of gene regulation network in reproductive tissues under drought stress are largely unknown. In this study, rice plants subjected to reproductive stage drought stress were examined for floral development and transcriptomic changes. The results showed that male fertility was dramatically affected, with differing pollen viability in flowers of the same panicle due to aberrant anther development under water stress. Examination of local starch distribution revealed that starch accumulated abnormally in terms of position and abundance in anthers of water-stressed plants. Microarray analysis using florets of different sizes identified >1000 drought-responsive genes, most of which were specifically regulated in only one or two particular sizes of florets, suggesting developmental stage-dependent responses to drought. Genes known to be involved in tapetum and/or microspore development, cell wall formation or expansion, and starch synthesis were found more frequently among the genes affected by drought than genome average, while meiosis and MADS-box genes were less frequently affected. In addition, pathways related to gibberellin acid signaling and abscisic acid catabolism were reprogrammed by drought. Our results strongly suggest interactions between reproductive development, phytohormone signaling, and carbohydrate metabolism in water-stressed plants.

Cytological and Transcriptomic Analyses Reveal Important Roles of CLE19 in Pollen Exine Formation

“…Inflorescences of wild-type and mutant plants were collected and fixed in FAA (formaldehyde-acetic acid-ethanol) solution and embedded in Technovit 7100 resin (Heraeus Kulzer) as described (Jin et al, 2013). Semithin sections were prepared by cutting inflorescence materials into 1-mm-thick sections using a motorized RM2265 rotary microtome (Leica Microsystems) and then were stained with 0.05% Toluidine Blue O for 15 to 30 min and photographed by bright-field microscopy.…”

Polyploidy enhances F1 pollen sterility loci interactions that increase meiosis abnormalities and pollen sterility in autotetraploid rice

“…Twenty-eight rice meiotic genes have been characterized to date (Luo et al, 2014), and more than 300 meiosis stage-specific genes have been identified in rice anthers (Fujita et al, 2010;Jin et al, 2013). Here, our main focus was on differentially down-regulated meiosis-related or stage-specific genes associated with the IPE factor.…”

“…The complexity of gene expression during anther and ovary development has been revealed using microarrays or RNA sequencing in diploid rice (Tang et al, 2010;Aya et al, 2011;Deveshwar et al, 2011;Jin et al, 2013;Pan et al, 2014), maize (Zea mays; DukowicSchulze et al, 2014), wheat (Triticum aestivum; Crismani et al, 2006), and Arabidopsis (Arabidopsis thaliana; Twell, 2003, 2004;Yang et al, 2011;Zhao et al, 2014). Microarrays have been used to identify differentially expressed genes in autotetraploid plants.…”

Características de tolerância à seca em genótipos de uma coleção nuclear de arroz de terras altas

“…A coincidência do estresse hídrico com a meiose das células dos grãos de pólen é o principal fator para esterilidade das espiguetas (Jin et al, 2013).…”

“…Em plantas sob essa condição, há aumento da resistência difusiva ao vapor de água mediante o fechamento dos estômatos, o que reduz a transpiração e o suprimento de CO 2 , além de diminuir o crescimento celular e aumentar a fotorrespiração (Shinozaki & Yamaguchi-Shinozaki, 2007). Esses efeitos resultam em perda de vigor, diminuição na altura da planta, aumento na esterilidade do grão de pólen e redução na produtividade (Jongdee et al, 2006;Jagadish et al, 2007;Jin et al, 2013).…”