RESUMEN
Cotton cytoplasmic male sterility (CMS) has been extensively studied; however, information regarding its molecular mechanisms has not yet been disclosed. Therefore, to explore the molecular mechanism of pollen abortion of cotton CMS line H276A, transcript profiles of 30 mitochondrial protein-encoding genes at tetrad stage were conducted with northern blot and a differential expression gene cox3 was identified. Quantitative reverse-transcribed PCR (qRT-PCR) analysis indicated that the expression level of cox3 in the CMS line H276A was 0.39-fold compared to its maintainer line H276B. In addition, the immunoblot analysis revealed that the amount of COX3 protein was decreased to 59.38% in CMS line H276A. The 5` and 3` terminals of the transcript of cox3 in two materials were determined simultaneously with circularized RNA reverse-transcribed PCR (CR-RT-PCR). The data indicated that seven 5` end of transcript of cox3 in H276A (-451/-464/-465/-467/-471/-472/-508 respect to ATG) were identified which were different from that of H276B (-411/-412). A total of 15 single nucleotide polymorphisms (SNPs) was detected by clone sequencing analysis of upstream of cox3. To our knowledge, we are the first to comprehensively analyze the transcripts of the mitochondrial genome in the cotton CMS line and to identify the 5` and 3` terminals of the transcript of cox3 in cotton. Our data will provide a framework for a better understanding of molecular mechanisms of CMS and mitochondrial gene expression in cotton.
Asunto(s)
Gossypium , Infertilidad Vegetal , Perfilación de la Expresión Génica/métodos , Regulación de la Expresión Génica de las Plantas , Genes Mitocondriales , Gossypium/genética , Gossypium/metabolismo , Infertilidad Vegetal/genéticaRESUMEN
Improving grain filling in the presernt farming systems is crucial where grain filling is a concern due to the extreme use of chemical fertilizers (CF). A field experiment was conducted at the experimental station of Guangxi University, China in 2019 to test the hypothesis that cattle manure (CM) and poultry manure (PM) combined with CF could improve rice grain filling rate, yield, biochemical and qualitative attributes. A total of six treatments, i.e., no fertilizer (T1), 100% CF (T2), 60% CM + 40% CF (T3), 30% CM + 70% CF (T4), 60% PM + 40% CF (T5), and 30% PM + 70% CF (T6) were used in this study. Results showed that the combined treatment T6increased starch metabolizing enzymes activity (SMEs), such as ADP-glucose phosphorylase (ADGPase) by 8 and 12%, soluble starch synthase (SSS) by 7 and 10%, granule bound starch synthesis (GBSS) by 7 and 9%, and starch branching enzyme (SBE) by 14 and 21% in the early and late seasons, respectively, compared with T2. Similarly, higher rice grain yield, grain filling rate, starch, and amylose content were also recorded in combined treatments. In terms of seasons, higher activity of SMEs , grain starch, and amylose content was noted in the late-season compared to the early season. The increment in these traits was mainly attributed to a lower temperature in the late season during the grain filling period. Furthermore, our results suggested that an increment in starch accumulation and grain filling rate were mainly associated with the enhanced sink capacity by regulating key enzyme activities involved in Suc-to-starch conversion. In-addition, RT-qPCR analysis showed higher expression levels of AGPS2b, SSS1, GBSS1, and GBSE11b genes, which resultantly increased the activities of SMEs during the grain filling period under combined treatments. Linear regression analysis revealed that the activity of ADGPase, SSS, GBSS, and SBE were highly positively correlated with starch and amylose accumulation. Thus, we concluded that a combination of 30% N from PM or CM with 70% N from CF is a promising option in terms of improving rice grain yield and quality. Our study provides a sustainable fertilizer management strategy to enhance rice grain yield and quality at the lowest environmental cost.