Project description:Using the HiSeqTM 2000 sequencing platform, the anther transcriptome of photo thermo sensitive genic male sterile lines (PTGMS) rice Y58S and P64S (Peiâai 64S) were analyzed at the fertility sensitive stage under cold stress.These datas would be most beneficial for further studies investigating the molecular mechanisms of rice responses to cold stress.
Project description:A biological phenomenon in which hybrids exhibit superior phenotypes from its parental inbred lines known as heterosis, has been widely exploited in plant breeding and extensively used in crop improvement. Hybrid rice has immense potential to increase yield over other rice varieties and hence is crucial in meeting increasing demand of rice globally. Moreover, the molecular basis of heterosis is still not fully understood and hence it becomes imperative to unravel its genetic and molecular basis. In this context, RNA sequencing technology (RNA-Seq) was employed to sequence transcriptomes of two rice hybrids, Ajay and Rajalaxmi, their parental lines, CRMS31A (sterile line, based on WA-CMS) and CRMS32A (sterile line based on Kalinga-CMS) respectively along with the common restorer line of both hybrids, IR-42266-29-3R at two critical rice developmental stages viz., panicle initiation (PI) and grain filling (GF). Identification of differentially expressed genes (DEGs) at PI and GF stages will further pave the way for understanding heterosis. In addition, such kind of study would help in better understanding of heterosis mechanism and genes up-regulated and down-regulated during the critical stages of rice development for higher yield.
Project description:An indica rice cultivar FR13A, is widely grown as submergence tolerant variety and can withstand submergence up to two weeks. The tolerance is governed by a major QTL on chromosome 9 and represented as sub1. Recently the gene for sub1 has been mapped and cloned. However, the trait is governed by several QTLs and not by a single gene. To understand the mechanism of submergence tolerance we selected, two indica rice genotypes namely, I) FR13A, a tolerant indica variety and ii) IR24, a susceptible genotype for this study. We used the 22K rice Oligoarray from Agilent technologies to study the transcript profile in the leaves of the two contrasting rice genotypes under constitutive and submerged conditions at seedling stage. Keywords: Mechanism of submergence tolerance
Project description:A submergence tolerant indica rice cultivar FR13A, was also reported to withstand salt stress and proven in our experiments. The mechanism of tolerance is yet to be studied by forward genetics approach. However, it is known that salt stress tolerance is governed by several QTLs and not by a single gene. To understand the mechanism of such a complex mechanism of salt tolerance we selected, two indica rice genotypes namely, I) FR13A, a tolerant indica variety and ii) IR24, a susceptible genotype for this study. We used the 22K rice Oligoarray from Agilent technologies to study the transcript profile in the leaves of the two contrasting rice genotypes under constitutive and salt stress conditions at seedling stage. Keywords: Mechanism of salt tolerance
Project description:Male sterility is an important trait in hybrid crop breeding. Thermo-sensitive genic male sterility (TGMS) lines, which are male-sterile at restrictive (high) temperatures but convert to male-fertile at permissive (low) temperatures, have been widely utilized in two-line hybrid rice breeding3. However, the molecular mechanism underlying TGMS remains unclear. Here we show that the rice (Oryza sativa L.) thermo-sensitive genic male sterile gene 5 (tms5) locus, which in 2010 was present in cultivars occupying more than 70% (2.4 million hectares) of two-line hybrid rice-growing land in China, confers the TGMS trait through a loss-of-function mutation of RNase ZS1, resulting in failure to mediate mRNA decay of three temperature-responsive ubiquitin fusion ribosomal protein L40 genes (UbL40). TMS5 encodes an evolutionarily conserved endonuclease, RNase ZS1. RNase ZS1 can process tRNAs in vitro, but does not do so in vivo due to its localization in the cytoplasm. Defective RNase ZS1 in tms5 plants leads to over-accumulation of UbL401, UbL402 and UbL404 mRNAs at restrictive but not permissive temperatures. Furthermore, over-expression of UbL401 and UbL404 in wild-type plants causes male sterility, while knockdown of UbL401 and UbL404 in tms5 partially restores its fertility. Our results uncover a novel mechanism of RNase ZS1-mediated UbL40 mRNA decay which controls TGMS in rice and has potential applications in hybrid breeding not only of rice but also of other crops. Examination of differences in mRNA accumulation between 93-11, NIL5 and NIL8.
Project description:Male sterility is an important trait in hybrid crop breeding. Thermo-sensitive genic male sterility (TGMS) lines, which are male-sterile at restrictive (high) temperatures but convert to male-fertile at permissive (low) temperatures, have been widely utilized in two-line hybrid rice breeding. However, the molecular mechanism underlying TGMS remains unclear. Here we show that the rice (Oryza sativa L.) thermo-sensitive genic male sterile gene 5 (tms5) locus, which in 2010 was present in cultivars occupying more than 71% (2.3 million hectares) of two-line hybrid rice-growing land in China, confers the TGMS trait through a loss-of-function mutation of RNase ZS1, resulting in failure to mediate mRNA decay of three temperature-responsive ubiquitin fusion ribosomal protein L40 genes (UbL40) genes. RNase ZS1, a member of the evolutionarily conserved endonuclease, processed tRNAs in vitro, but does not do so in vivo due to its localization in the cytoplasm. Defective RNase ZS1 in tms5 plants leads to over-accumulation of UbL401, UbL402 and UbL404 mRNAs at restrictive but not permissive temperatures. Over-expression of UbL401 and UbL404 in wild-type plants caused male sterility, whereas knockdown of UbL401 and UbL404 in tms5 plants partially restored the male fertility at restrictive temperatures. Our results uncover a novel mechanism of RNase ZS1-mediated UbL40 mRNA decay which controls TGMS in rice and has potential applications not only of rice but also of other crops.
Project description:Male sterility is an important trait in hybrid crop breeding. Thermo-sensitive genic male sterility (TGMS) lines, which are male-sterile at restrictive (high) temperatures but convert to male-fertile at permissive (low) temperatures, have been widely utilized in two-line hybrid rice breeding. However, the molecular mechanism underlying TGMS remains unclear. Here we show that the rice (Oryza sativa L.) thermo-sensitive genic male sterile gene 5 (tms5) locus, which in 2010 was present in cultivars occupying more than 80% (2.6 million hectares) of two-line hybrid rice-growing land in China, confers the TGMS trait through a loss-of-function mutation of RNase ZS1, resulting in failure to mediate mRNA decay of three temperature-responsive ubiquitin fusion ribosomal protein L40 genes (UbL40) genes. RNase ZS1, a member of the evolutionarily conserved endonuclease, processed tRNAs in vitro, but does not do so in vivo due to its localization in the cytoplasm. Defective RNase ZS1 in tms5 plants leads to over-accumulation of UbL401, UbL402 and UbL404 mRNAs at restrictive but not permissive temperatures. Over-expression of UbL401 and UbL404 in wild-type plants caused male sterility, whereas knockdown of UbL401 and UbL404 in tms5 plants partially restored the male fertility at restrictive temperatures. Our results uncover a novel mechanism of RNase ZS1-mediated UbL40 mRNA decay which controls TGMS in rice and has potential applications not only of rice but also of other crops.