Key message

Among the five cassava isoforms (MeAPL1–MeAPL5), MeAPL3 is responsible for determining storage root starch content. Degree of storage root postharvest physiological deterioration (PPD) is directly correlated with starch content.

Abstract

AGPase is heterotetramer composed of two small and two large subunits each coded by small gene families in higher plants. Studies in cassava (Manihot esculenta) identified and characterized five isoforms of Manihot esculenta ADP-glucose pyrophosphorylase large subunit (MeAPL1–MeAPL5) and employed virus induced gene silencing (VIGS) to show that MeAPL3 is the key isoform responsible for starch and dry matter accumulation in cassava storage roots. Silencing of MeAPL3 in cassava through stable transgenic lines resulted in plants displaying significant reduction in storage root starch and dry matter content (DMC) and induced a distinct phenotype associated with increased petiole/stem angle, resulting in a droopy leaf phenotype. Plants with reduced starch and DMC also displayed significantly reduced or no postharvest physiological deterioration (PPD) compared to controls and lines with high DMC and starch content. This provides strong evidence for direct relationships between starch/dry matter content and its role in PPD and canopy architecture traits in cassava.

中文翻译：

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木薯 shrunken-2 同源物 MeAPL3 决定贮藏根淀粉和干物质含量，并调节贮藏根采后生理退化。

关键信息

在五种木薯同种型 ( MeAPL1 – MeAPL5 ) 中，MeAPL3 负责确定贮藏根淀粉含量。贮藏根采后生理变质（PPD）程度与淀粉含量直接相关。

抽象的

AGPase 是由高等植物中的小基因家族编码的两个小亚基和两个大亚基组成的异四聚体。对木薯 (Manihot e sculenta) 的研究确定并表征了 Manihot e sculenta A DP-葡萄糖焦磷酸化酶大亚基 (MeAPL1 – MeAPL5) 的五种同工型，并采用病毒诱导 基因 沉默( VIGS )表明MeAPL3是关键同工型负责木薯贮藏根中淀粉和干物质的积累。MeAPL3的沉默   在木薯中，通过稳定的转基因品系导致植物的贮藏根淀粉和干物质含量 (DMC) 显着降低，并诱导了与叶柄/茎角增加相关的独特表型，从而导致叶片下垂表型。与对照和具有高 DMC 和淀粉含量的品系相比，具有减少的淀粉和 DMC 的植物也显示出显着减少或没有采后生理恶化 (PPD)。这为淀粉/干物质含量与其在 PPD 和木薯冠层结构特征中的作用之间的直接关系提供了强有力的证据。