Different gene expression patterns of sucrose‐starch metabolism during pollen maturation in cytoplasmic male‐sterile and male‐fertile lines of rice
Different gene expression patterns of sucrose‐starch metabolism during pollen maturation in cytoplasmic male‐sterile and male‐fertile lines of rice
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DOI：
10.1111/j.1399-3054.2007.00877.x
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发表时间：
2007-05
影响因子：
6.4
通讯作者：
Jin Kong;Zhong Li;Yanping Tan;Cuixiang Wan;Shaoqing Li;Ying-guo Zhu
中科院分区：
文献类型：
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作者：
Jin Kong;Zhong Li;Yanping Tan;Cuixiang Wan;Shaoqing Li;Ying-guo Zhu
淀粉的生物合成是花粉发育过程中一个非常关键的过程，但在基因调控和细胞内调控方面还没有得到很好的理解。利用花粉淀粉缺乏的水稻hl型细胞质雄性不育系（HL-CMS）和两个相关的雄性可育系（Oryza sativa L.），我们研究了两个特定的发育阶段：“早期”，即花粉有丝分裂I期之前或期间，没有淀粉积累；“晚期”，即花粉有丝分裂I期后淀粉填充活跃。实时逆转录- pcr分析显示蔗糖-淀粉途径相关的6个代谢基因，即蔗糖合成酶（EC 2.4.1.13）、Rsus3；酸性转化酶（EC 3.2.1.26）；磷酸葡萄糖糖化酶（EC 5.4.2.2）；尿苷二磷酸-葡萄糖焦磷酸化酶（EC 2.7.7.9）， OsUGP，二磷酸腺苷-葡萄糖焦磷酸化酶（EC 2.2.7.2）的亚基OsAGPL3；可溶性淀粉合成酶（EC 2.4.1.21）、OsSSI和三个转运基因[蔗糖转运蛋白OsSUT3；己糖转运蛋白OSMST7和质膜H + -腺苷三磷酸酶（ATPase） （EC 3.6.1.35）， OSA2]。在代谢酶活性方面，3个水稻品系的蔗糖合酶活性在“后期”较“早期”低；转化酶和其他下游酶在雄性可育系的后期活性较高，而雄性不育系的后期活性较低。与此同时，与男性可育组织相比，在雄性不育组织的“早期”和“晚期”阶段检测到糖和ATP水平显著降低。此外，转基因数据表明，AGPase基因可以刺激淀粉在雄性不育寄主花粉中的积累，表明AGPase在代谢途径中的重要性。综上所述，这些数据表明，淀粉生物合成过程中能量供应和糖水平的降低可能导致基因表达的时间变化，最终导致花粉不育。
Starch biosynthesis, a very critical event during pollen development, is not well understood in terms of gene regulation and intracellularcontrols. Using the rice HL-type cytoplasmic male sterile (HL-CMS) line with starch deficiency in pollen and two related male-fertile lines (Oryza sativa L.), we have studied two specific developmental stages: 'early', that is, before or during pollen mitosis I, without starch accumulation, and 'late', the actively starch-filling postpollen mitosis I phase. Real-time reverse transcription-PCR analysis showed temporal changes in the expression patterns of six metabolic genes involved in the sucrose-starch pathway, i.e. sucrose synthase (EC 2.4.1.13), Rsus3; acid invertase (EC 3.2.1.26), OSINV2; phosphoglucomutase (EC 5.4.2.2), OsPGM; uridine diphosphate-glucose pyrophosphorylase (EC 2.7.7.9), OsUGP, a subunit of adenosine diphosphate-glucose pyrophosphorylase (AGPase) (EC 2.2.7.2), OsAGPL3; soluble starch synthase (EC 2.4.1.21), OsSSI and three transporter genes [sucrose transporter, OsSUT3; hexose transporter, OSMST7 and plasma membrane H + -adenosine triphosphatase (ATPase) (EC 3.6.1.35), OSA2]. Regarding metabolic enzyme activities, lower activity of sucrose synthase was detected at 'late' compared with 'early' stage in the three rice lines; invertase and other downstream enzymes had higher activities at 'late' stage in male-fertile but not male-sterile lines. Meanwhile, significantly reduced sugars and ATP levels were detected at 'early' and 'late' stages in male-sterile compared with male-fertile tissues. Furthermore, transgenic data showed that AGPase gene can stimulate starch accumulation in pollen of male-sterile host lines, showing the importance of AGPase in the metabolic pathway. Taken together, these data suggest that the combined effects of the reduced energy supply and sugar levels in starch biosynthesis may lead to the observed temporal changes in gene expression, and eventually to pollen sterility.