RNAi: nematode-resistant tobaccoRNAi: सूत्रकृमि-प्रतिरोधी तंबाकू

NCERT Fig 10.2 · Class 12 Biology · Chapter 10 · interactive diagram

Parts and their functions

• Agrobacterium vector (एग्रोबैक्टीरियम वाहक) — Used as the vector to carry nematode-specific genes into the host (tobacco) plant.
• Nematode-specific gene (सूत्रकृमि-विशिष्ट जीन) — A gene (DNA) copied from the nematode, inserted so that the host makes RNA matching the nematode.
• Host (tobacco) plant cell (पोषी (तंबाकू) पादप कोशिका) — The transgenic host plant cell expresses the introduced DNA.
• Introduced DNA (डाला गया DNA) — The DNA was introduced in such a way that it produced BOTH sense and anti-sense RNA in the host cells.
• Sense RNA (सेंस RNA) — One RNA strand made from the introduced gene.
• Anti-sense RNA (एंटीसेंस RNA) — The complementary RNA strand; it pairs with the sense RNA.
• dsRNA (double-stranded RNA) (dsRNA (द्विरज्जुकी RNA)) — Sense + anti-sense RNA are complementary, so they form dsRNA — this starts RNA interference (RNAi).
• Meloidegyne incognita (nematode) (मेलॉयडोगाइन इनकोग्निटा (सूत्रकृमि)) — A nematode that infects the roots of tobacco plants and greatly reduces yield.
• Nematode mRNA silenced (सूत्रकृमि mRNA निष्क्रिय) — The dsRNA binds the specific mRNA of the nematode and prevents its translation (silencing). The parasite cannot survive in the transgenic host.
• (a) Control plant roots ((a) सामान्य पौधे की जड़ें) — Roots of a normal (non-transgenic) plant — infested and damaged by the nematode.
• (b) Transgenic plant roots ((b) पारजीनी पौधे की जड़ें) — Roots of the transgenic plant 5 days after deliberate nematode infection — protected.

Steps

1. Using an Agrobacterium vector, nematode-specific genes are put into the host plant.
2. The host cell makes both sense and anti-sense RNA.
3. The two complementary RNAs join → double-stranded RNA (dsRNA).
4. The nematode feeds on the root.
5. dsRNA binds the nematode’s specific mRNA → no translation (silenced).
6. The parasite cannot survive; transgenic roots stay protected.

Original diagram drawn by Simple Learning Hub, based on NCERT Fig 10.2. Report a mistake