×

UPSC Courses

DNA banner

DAILY NEWS ANALYSIS

  • 27 December, 2020

  • 7 Min Read

How do conifers keep their green needles over the boreal winter?

How do conifers keep their green needles over the boreal winter?

  • During boreal winter most trees shed their leaves. However, conifers such as Christmas trees keep their green needles intact.
  • Scientists believe that a phenomenon called sustained quenching offers photoprotection and enables their survival, but its precise molecular and physiological mechanisms are not understood.
  • Researchers have now found that the photosynthetic apparatus is wired in a special way which allows pine needles to stay green all year long.
  • In winter, green chlorophyll molecules harness light energy, but that energy cannot be used in the photosynthetic machinery as very low-temperature halts most biochemical reactions.
  • However, in early spring, even as temperatures are low, there is plenty of sunlight. The excess light energy can damage the photosynthetic machinery’s proteins.
  • Under normal conditions, the two photosystems, the two functional units where light energy is absorbed and converted into chemical energy, are kept apart from each other to prevent a shortcut and allow efficient photosynthesis.
  • According to a study published in Nature Communications, a team of researchers found that in winter, the two photosystems are brought in physical contact with each other through reorganization of the structure of the thylakoid membrane, where the two photosystems are located.
  • Photosystem II donates energy directly to photosystem I and this short­cut mode protect the green chlorophyll and the needles when conditions become harsh.

Source: Science Daily


India–Azerbaijan

A year after tensions arising from Operation Sindoor, India and Azerbaijan have taken steps to restore and normalise bilateral relations. The 6th round of Foreign Office Consultations, held in Baku, marked the first such engagement since 2022, signaling renewed diplomatic momentum. Recent Diplomatic Engagement During the consultations, bo

India–Australia Economic Cooperation and Trade Agreem

The India–Australia Economic Cooperation and Trade Agreement has completed four years since its signing. Both countries now aim to build on this progress through strengthened collaboration and ambitious targets, including reaching AUD 100 billion in bilateral trade by 2030. What is the India–Australia Economic Cooperation and Tra

ADR Report on Political Funding

A recent report by the Association for Democratic Reforms (ADR) analyses donations of ?20,000 or more declared to the Election Commission of India (ECI) by national political parties for FY 2024–25, highlighting transparency and accountability in political financing. Key Findings Massive Funding Surge Total donations to nationa

Maritime Chokepoints

Maritime chokepoints are narrow channels along global shipping routes where maritime traffic is concentrated. These points are geopolitically and economically critical, as they handle a large proportion of global trade, especially energy shipments. Current Relevance Over two-thirds of seaborne energy trade passes through a handful o

US-Israel-Iran War

Following the launch of Operation Epic Fury (U.S.) and Operation Roaring Lion (Israel), the geopolitical landscape has shifted fundamentally with the confirmed death of Iran’s Supreme Leader, Ayatollah Ali Khamenei.Iran retaliated through Operation True Promise 4, launching missile attacks against Israel and nearby Gulf states. The escala

DNA

05 Apr,2026

Toppers

Search By Date

Newsletter Subscription
SMS Alerts

Important Links

UPSC GS Mains Crash Course - RAW