Key message

Os4BGlu14, a monolignol β-glucosidase, plays a negative role in seed longevity by affecting primary metabolism during seed development and aging.

Abstract

Seed longevity is a crucial trait in agriculture and in the conservation of germplasm resources. β-Glucosidases (BGlus) are multifunctional enzymes that affect plant growth and their adaptation to the environment. The function of rice BGlus in seed longevity, however, remains unknown. We report here that Os4BGlu14, a rice β-Glucosidase, negatively affected seed longevity during accelerated aging. Os4BGlu14 was highly expressed in rice embryos and induced by accelerated aging. Compared to the wild type, rice lines overexpressing Os4BGlu14 had significantly greater grain length, but smaller grain width and thickness. Overexpressing (OE) lines also showed lower starch but higher glucose contents. After accelerated aging treatment, OE lines displayed a significantly lower germination percentage than the wild type. Additionally, these lines had higher lignin accumulation before and after accelerated aging. Metabolome analysis detected 217 metabolites in untreated and aged rice seeds. Comparison of the differential metabolites between WT and OE5 revealed that ten key metabolites, four of which (e.g., uridine 5′-diphosphoglucose-glucose, UDPG) were increased, while the other six (e.g., γ-aminobutyric acid and methionine) were decreased, might be the crucial factors that lead to seed deterioration. Further analysis confirmed higher UDPG levels and more severe programmed cell death in OE lines than in the wild type. Furthermore, OE lines presented a lower germination rate after abscisic acid and paclobutrazol treatment during germination, compared to the wild type. Our study provides a basis for understanding the function of Os4BGlu14 in seed longevity in rice.

中文翻译：

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Os4BGlu14 是一种单木酚 β-葡萄糖苷酶，通过影响水稻的初级代谢对种子寿命产生负面影响。

关键信息

Os4BGlu14 是一种单木酚β-葡萄糖苷酶，通过影响种子发育和衰老过程中的初级代谢，对种子寿命产生负面影响。

抽象的

种子寿命是农业和种质资源保护的关键性状。β-葡萄糖苷酶 (BGlus) 是影响植物生长及其对环境适应的多功能酶。然而，水稻 BGlus 在种子寿命中的作用仍然未知。我们在此报告 Os4BGlu14，一种水稻β-葡萄糖苷酶，在加速老化过程中对种子寿命产生负面影响。Os4BGlu14 在水稻胚胎中高表达，并受加速衰老的诱导。与野生型相比，过表达Os4BGlu14的水稻品系的粒长显着增加，但粒宽和厚度更小。过表达 (OE) 系也显示出较低的淀粉但较高的葡萄糖含量。加速老化处理后，OE系的发芽率明显低于野生型。此外，这些品系在加速老化前后具有较高的木质素积累。代谢组分析在未经处理和老化的水稻种子中检测到 217 种代谢物。WT 和 OE5 之间差异代谢物的比较揭示了 10 个关键代谢物，其中 4 个（例如，尿苷 5'-二磷酸葡萄糖-葡萄糖，UDPG）增加了，γ-氨基丁酸和蛋氨酸）减少，可能是导致种子劣化的关键因素。进一步的分析证实 OE 系中的 UDPG 水平比野生型更高，程序性细胞死亡更严重。此外，与野生型相比，OE 品系在发芽期间经脱落酸和多效唑处理后的发芽率较低。我们的研究为了解Os4BGlu14在水稻种子寿命中的作用提供了依据。