Genetic Control of Regeneration

पुनरुद्धभवन का आनुवंशिक नियंत्रण (Genetic Control of Regeneration):-

1. परिचय (Introduction):-

·         पादपों में क्षति से रिकवर होने की शक्तिशाली पुनरुद्धभवन क्षमता विकसित हो चुकी है।

(The plants have developed a powerful regenerative ability to recover from damage.)

·         पादप पुनरुद्धभवन का अध्ययन अत्यधिक महत्व का होता है क्योंकि पादप पुनरुद्धभवन की क्रियाविधि:-

(The study of plant regeneration is of great importance because the mechanism of plant regeneration is:)

i. अनेक क्षेत्रों में आधारभूत अनुसंधान से संबन्धित होती है।

(related to basic research in many areas.)

ii. विस्तृत रूप से उपयोग की जाने वाली पादप जैवप्रौधौगिकी से संबन्धित होती है।

(related to plant biotechnology which is extensively used.)

·         उच्च पादप 3 मुख्य प्रकार का पुनरुद्धभवन प्रदर्शित करते हैं:-

(Higher plants exhibit 3 main types of regeneration: -)

i. ऊत्तक पुनरुद्धभवन (Tissue regeneration)

ii. डी नोवो अंगजनन (de novo organogenesis)

iii. कायिक भ्रूणजनन (Somatic embryogenesis)

·         आधुनिक खोज से यह पता चला है कि पादप हार्मोन्स पुनरुद्धभवन को ट्रिगर करते हैं। अनेक ट्रांसक्रिप्शन कारक हार्मोन के सिग्नल के प्रति प्रतिक्रिया देते हैं ताकि कोशिका के भविष्य को निर्धारित किया जा सके।

(Modern research has shown that plant hormones trigger regeneration. Many transcription factors respond to hormonal signals to determine the fate of the cell.)

·         कोशिका के भविष्य को निर्धारित करने के लिए जीनों की अभिव्यक्ति के नियमन की आवश्यकता होती है। जीनों की अभिव्यक्ति के नियमन के लिए ट्रांसक्रिप्शन कारकों को कुछ ऐपीजेनेटिक कारकों की भी आवश्यकता होती है।

(Regulation of the gene expression is required to determine the fate of the cell. Transcription factors also require some epigenetic factors to regulate the expression of genes.)

·         इस प्रकार पुनरुद्धभवन के आनुवांशिक नियंत्रण के लिए 3 मुख्य कारक आवश्यक होते हैं:-

(Thus 3 main factors are necessary for genetic control of regeneration:-)

i.  हार्मोन सिगनल्स (Hormone signals)

ii.  ट्रांसक्रिप्शन कारक (Transcription factors)

iii.  ऐपीजेनेटिक कारक (Epigenetic factors)

·         चूंकि पुनरुद्धभवन घाव से शुरू होता है, इसलिए घाव सिग्नल की पहचान करना भविष्य में अनुसंधान के लिए एक महत्वपूर्ण उद्देश्य हो सकता है।

(Since regeneration begins with a wound, identification of the wound signal may be an important objective for future research.)

2. आनुवंशिक नियंत्रण (Genetic Control):- 

·         गाजर की कोशिकाओं में कायिक भ्रूणजनन की बहुत अधिक क्षमता पायी जाती है।

(Carrot cells have a very high capacity of somatic embryogenesis.)

·         EP-3 जीन की अभिव्यक्ति (Expression of EP - 3 gene):- गाजर के पौधों में इसकी अभिव्यक्ति कायिक भ्रूण के अंदर न होकर इसके चारों ओर की कोशिकाओं में होती है जो भ्रूण के पोषण में भाग लेती हैं।

(In carrot plants, expression of EP - 3 gene is not inside the somatic embryo, but it is in the cells around it that participate in the nutrition of the embryo.)

·         Chicory पौधे में अध्ययन से यह प्रदर्शित होता है कि इस पौधे में 3 Pathogenesis related proteins की अभिव्यक्ति के कारण कायिक भ्रूणजनन सम्पूर्ण होता है:-

(Studies in the chicory plant show that the somatic embryogenesis complete in this plant is due to the expression of 3 Pathogenesis related proteins:-)

i.   38KDa Glucanase

ii.   32KDa Chitinase

iii.   25KDa Osmotin like protein

Chitinase व Glucanase एंजाइम्स विकसित हो रहे कायिक भ्रूण के चारों ओर की कोशिकाओं की कोशिका भित्ति के घटकों के विघटन में भाग लेते हैं। जो कायिक भ्रूण के पोषण को बढ़ा देते हैं। यह भी संभव है कि ये दोनों एंजाइम्स कोशिका भित्ति से सिग्नल अणुओं को छोड़ते हैं जो कायिक भ्रूण के विकास के लिए आवश्यक होते हैं।

(Chitinase and Glucanase enzymes participate in the dissolution of the components of the cell wall of cells around the developing somatic embryo. Which increase the nutrition of the somatic embryo. It is also possible that both of these enzymes release signal molecules from the cell wall that are essential for the development of the somatic embryo.)

·         गाजर की कोशिकाओं में SERK जीन की पहचान की गई है। 

(The SERK gene has been identified in carrot cells.)

(SERK = Somatic Embryogenesis Receptor like Kinase)

·         SERK जीन की अभिव्यक्ति (Expression of SERK gene):- यह उन कोशिकाओं में शुरू होती है जो कायिक भ्रूणजनन परिपथ में प्रवेश करती हैं। Globular stage के बाद इसकी अभिव्यक्ति रुक जाती है।

(It begins in cells that enter the somatic embryogenesis pathway. Its expression stops after the globular stage.)

·         Arabidopsis thaliana से SERK के समजात एक जीन को क्लोन किया गया है:- AtSERK1

इसकी अभिव्यक्ति विकसित हो रहे बीजाण्ड में शुरू होती है तथा Heart stage तक चलती रहती है।

(A gene homologous to SERK has been cloned from Arabidopsis thaliana:- AtSERK1

Its expression starts in the developing ovule and continues till the heart stage.)