{
  "id": 10703708,
  "title": "Loss of starch synthase IIa alleviates the negative impact of high temperature on rice starch during grain filling",
  "url": "https://urgent.news/2026/09/29/loss-of-starch-synthase-iia-alleviates-the-negative-impact-of-high",
  "topic": "science",
  "section": "Science",
  "published": "2026-09-29T00:00:00.000Z",
  "source": {
    "name": "bioRxiv",
    "slug": "biorxiv",
    "url": "https://www.biorxiv.org/content/10.64898/2026.09.28.754565v1?rss=1"
  },
  "original_language": "en",
  "account": "High temperatures during the grain filling stage of rice cultivation are becoming more common, negatively impacting both grain and eating quality. This leads to a reduction in desirable traits such as amylose content and an increase in long-chain amylopectin. To address this issue, a functional mutation was introduced in starch synthase IIa (SSIIa) to increase the proportion of short amylopectin chains, which compensates for the high-temperature-induced rise in amylopectin long chain. Rice lines carrying this ss2a mutation were grown at two locations with differing temperatures to evaluate their grain traits, starch structure, and eating quality. While the ss2a mutant lines exhibited an increased proportion of short amylopectin chains and an increased apparent amylose content, the alterations in starch structure varied depending on the grain-filling temperature of the cultivation sites. These changes ultimately influenced the eating quality of the rice. The findings suggest that enriching short amylopectin chains through the ss2a mutation can counteract the negative effects of high temperatures during grain filling, helping to maintain a desirable starch structure and eating quality in rice cultivars.",
  "summary": "High temperatures during grain filling stage are becoming increasingly frequent, compromising both grain and eating quality and thereby driving demand for heat-resilient cultivars. Such conditions are known to reduce the expression of granule-bound starch synthase I (GBSSI) and starch branching enzyme IIb (BEIIb), which are involved in starch biosynthesis, resulting in a decrease in amylose…",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}